Ashford University MAT 232 MIDTERM EXAM LATEST SOLUTION
What is a sample statistic, what is a population parameter, and what is the difference between
... [Show More] them? What is a sample statistic?
A. A sample statistic is a range of likely values that a population parameter could take.
B. A sample statistic is a numerical value describing some attribute of a population.
C. A sample statistic is a numerical value describing some attribute of a sample. This is the correct answer
D. A sample statistic is a portion of the entities of interest that the researcher uses to gather data.
What is a population parameter?
A. A population parameter is a numerical value describing some attribute of a population.
B. A population parameter is a numerical value describing some attribute of a sample.
C. .A population parameter is a portion of the entities of interest that the researcher uses to gather data.
D. D.A population parameter is a range of likely values that a sample statistic could take.
What is the difference between a sample statistic and a population parameter?
A. A population parameter is frequently impractical or impossible to find for large populations, however a sample statistic is often easier to find and provides a reasonable approximation to the population parameter.
B. A sample statistic is frequently impractical or impossible to find for large samples, however a population parameter is often easier to find and provides a reasonable approximation to the sample statistic.
C. A sample statistic is a subset of a population parameter.
D. A population parameter is a subset of a sample statistic.
E. There is no difference between a sample statistic and a population parameter.
The following table gives the total area in square miles (land and water) of seven states. Complete parts (a) through (c).
State Area
1 52,100
2 615,100
3 114,500
4 53,200
5 158,900
6 104,700
7 5,800
a. Find the mean area and median area for these states.
The mean is 157,757 square miles. (Round to the nearest integer as needed.) The median is 104,700 square miles.
b. Which state is an outlier on the high end? If you eliminate this state, what are the new mean and median areas for this data set?
State 2 is an outlier on the high end.
The new mean is 81,533 square miles. (Round to the nearest integer as needed.) The new median is 78,950 square miles. (Round to the nearest integer as needed.)
c. Which state is an outlier on the low end? If you eliminate this state, what are the new mean and median areas for this data set?
State 7 is an outlier on the low end.
The new mean is 183,083 square miles. (Round to the nearest integer as needed.) The new median is 109,600 square miles. (Round to the nearest integer as needed.)
A mathematician drilled a hole in a die, filled it with a lead weight, and then proceeded to roll it. The results are given in the following frequency table.
Click the icon to view the frequency table.
Outcome Frequency
1 26
2 30
3 43
4 40
5 29
6 32
a. According to the data, how many times was the die rolled?
(Simplify your answer.)
b. How many times was the outcome greater than 2?
(Simplify your answer.)
c. What percentage of outcomes were 6?
(Type a whole number.)
d. List the relative frequencies as decimals or integers, not percentages, that correspond to the given frequencies. Complete the table below.
Outcom e
1
2
3
Relative frequency
4
5
6
(Type integers or decimals rounded to the nearest thousandth as needed.)
e. List the cumulative frequencies that correspond to the given frequencies. Complete the table below.
Outcom e
1
2
3
Cumulative frequency
4
5
6
(Simplify your answers.)
Fill in the blank in the following statement.
If a truck weighs 20% more than a car, then the truck's weight is % of the car's weight. If a truck weighs 20% more than a car, then the truck's weight is 120 % of the car's weight.
One common system for computing a grade point average (GPA) assigns 4 points to an A, 3 points to a B, 2 points to a C, 1 point to a D, and 0 points to an F. What is the GPA of a student who gets an A in a 3-credit course, a B in each of three 4-credit courses, a C in a 4-credit course, and a D in a 3-credit course?
The mean grade point score is
2.7.
(Round to the nearest tenth as needed.)
State whether the data described below are discrete or continuous, and explain why. The durations of movies in minutes
Choose the correct answer below.
A. The data are continuous because the data can only take on specific values.
B. The data are discrete because the data can only take on specific values.
C. The data are continuous because the data can take on any value in an interval.
D. The data are discrete because the data can take on any value in an interval.
A data set consists of the 80 ages of women at the time that they won an award in the category of best actress. Complete parts (a) through (c) below.
a. One of the actresses was 40 years of age, and she was older than 59 of the other actresses at the time that they won awards. What is the percentile of the age of 40?
37th percentile 71st percentile
73rd percentile 86th percentile
b. One of the actresses was 54 years of age, and she was older than 69 of the other actresses at the time that they won awards. What is the percentile of the age of 54?
32nd percentile 77th percentile 86th percentile 3rd percentile
c. One of the actresses was 60 years of age, and she was older than 70 of the other actresses at the time that they won awards. What is the percentile of the age of 60?
84th percentile 69th percentile 87th percentile 71st percentile
Construct a stem-and-leaf plot of the test scores
67 comma 72 comma 85 comma 75 comma 89 comma 89 comma 87 comma 90 comma 98 comma
100.67, 72, 85, 75, 89, 89, 87, 90, 98, 100.
How does the stem-and-leaf plot show the distribution of these data? Construct the stem-and-leaf plot. Choose the correct answer below.
A.
Ste m
Leaves
6 7
7 2 5
8 5 7 9 9
9 0 8
10 0
This is the correct answer.
B.
Ste m
Leaves
6 7
7 2 5
8 5 9 9 6
9 0 8
10 0
Your answer is not correct.
C.
Ste m
Leaves
6 7
7 26
8 5 6 9 7
9 0 9
10 0
D.
Ste m
Leaves
6 5
7 2 5
8 5 9 9 7
9 0 7
10 0
How does the stem-and-leaf plot show the distribution of these data?
A.
The lengths of the rows are similar to the heights of bars in a histogram; longer rows of data correspond to smaller frequencies.
B.
The lengths of the rows are similar to the widths of bars in a histogram; longer rows of data correspond to higher frequencies.
C.
The lengths of the rows are similar to the widths of bars in a histogram; longer rows of data correspond to smaller frequencies.
Your answer is not correct.
D.
The lengths of the rows are similar to the heights of bars in a histogram; longer rows of data correspond to higher frequencies.
Use the following frequency table for the weights (in pounds) of 4141
cans of regular coke with bin width of 0.0050 pound to construct the corresponding histogram.
Click the icon to view the table. Choose the correct graph below.
A.
0.790.83025WeightFrequency
•
•
•
A histogram has a horizontal axis labeled “Weight” from 0.79 to 0.83 in intervals of 0.01 and a vertical axis labeled “Frequency” from 0 to 25 in intervals of 5. The heights of the vertical bars with bin width 0.005 are as follows: 0.79 to 0.795, 2; 0.795 to 0.80, 0; 0.80 to 0.805, 2;
0.805 to 0.81, 16; 0.81 to 0.815, 5; 0.815 to 0.82, 3; 0.82 to 0.825, 8; 0.825 to 0.83, 5.
B.
0.790.83025WeightFrequency
•
•
•
A histogram has a horizontal axis labeled “Weight” from 0.79 to 0.83 in intervals of 0.01 and a vertical axis labeled “Frequency” from 0 to 25 in intervals of 5. The heights of the vertical bars with bin width 0.005 are as follows: 0.79 to 0.795, 2; 0.795 to 0.80, 0; 0.80 to 0.805, 2;
0.805 to 0.81, 3; 0.81 to 0.815, 5; 0.815 to 0.82, 5; 0.82 to 0.825, 8; 0.825 to 0.83, 16.
C.
0.790.83025WeightFrequency
•
•
•
A histogram has a horizontal axis labeled “Weight” from 0.79 to 0.83 in intervals of 0.01 and a vertical axis labeled “Frequency” from 0 to 25 in intervals of 5. The heights of the vertical bars with bin width 0.005 are as follows: 0.79 to 0.795, 2; 0.795 to 0.80, 0; 0.80 to 0.805, 2;
0.805 to 0.81, 3; 0.81 to 0.815, 5; 0.815 to 0.82, 16; 0.82 to 0.825, 8; 0.825 to 0.83, 5.
Your answer is correct.
D.
0.790.83025WeightFrequency
•
•
•
Statistics students participated in an experiment to test their ability to determine when 1 minute (or 60 seconds) has passed. The results are given below in seconds. Find the range and standard deviation for the given sample data.
52 52 61 70 57
Range =18 sec
Sample standard deviation = 7.5 sec (Round to the nearest tenth as needed.)
In a poll,
1,003 adultsadults in a certain country were asked whether they favor or oppose the use of "federal tax dollars to fund medical research using stem cells obtained from human embryos." Based on the poll results, it is estimated that 47% of adults are in favor, with a margin of error of 3 percentage points. Use the given statistic and margin of error to identify the range of values (confidence interval) likely to contain the true value of the population parameter.
The range of values likely to contain the population parameter is from
44%
to
50%.
(Simplify your answer. Use ascending order.)
In a poll, 1,002 adults in a certain country were asked whether they favor or oppose the use of "federal tax dollars to fund medical research using stem cells obtained from human embryos." Based on the poll results, it is estimated that 46% of adults are in favor, with a margin of error of 4 percentage points. Use the given statistic and margin of error to identify the range of values (confidence interval) likely to contain the true value of the population parameter.
The range of values likely to contain the population parameter is from
42%
to
50%.
(Simplify your answer. Use ascending order.)
. The number of daily newspapers is now 1,461, and it was 2,238 in 1900. Express the relative change using a percentage. Use the second given value as the reference value. Also, write a statement describing the result.
The relative change between the current year and 1900 is
−35%.
(Round to the nearest integer as needed.) There is a
35%
decrease from 1900. The number of daily newspapers is now 1,463, and is 2,222 in 1900. Express the relative change using a percentage. Use the second given value as the reference value. Also, write a statement
describing the result.
The relative change between the current year and 1900 is
−34%.
(Round to the nearest integer as needed.) There is a
34%
decrease from 1900.
Twenty-five people, consisting of a statistics professor and her students, are to measure the length of a room to the nearest tenth of a millimeter. Assume that everyone uses the same well- calibrated measuring device, such as a tape measure. Complete parts a through d below.
a. All 25 measurements are not likely to be exactly the same; thus, the measurements will contain some sources of error. Are these errors systematic or random? Explain.
A. These errors are random, because there is a tendency for the measurements to be all too high or too low.
B. These errors are random. If they were systematic, there would be a tendency for the measurements to be all too high or all too low.
C. These errors are systematic. If they were random, it would be undeterminable whether the measurements are all too high or too low.
D. These errors are systematic, because it is undeterminable whether the measurements are too high or too low.
b. If the professor wants to minimize the effect of random errors in determining the length of the room, is it better to report her own personal measurement as the length of the room or to report the average of all 25 measurements? Explain.
A. It is better to use the professor's own personal measurement because she has a more precise tape measure than her students.
B. It is better to use the average because it is likely to be in error by less than most of the individual measurements and it is more reliable than any single measurement.
C. It is better to use the professor's own personal measurement because the random errors in the individual measurements will be multiplied in size 25 times in the average.
D. It is better to use the average because the average of many measurements is always equal to the true value.
c. Describe any possible sources of systematic errors in the measurement of the room length.
A. Systematic errors might result if the tape measure has a manufacturing defect that made all of the units too small on the tape.
B. Systematic errors might result if the students rush, and do not make the measurements carefully.
C. Systematic errors might result if there isn't much light in the room and the professor and students misread the tape measure.
D. Systematic errors might result if the tape measure is not long enough, and the students need to sum the measurements from the walls to some central point in the room.
d. Can the process of averaging all 25 measurements help reduce any systematic errors? Why or why not?
A. No, because if there is a systematic error in the measurements, that same error will be present in the average.
B. Yes, because the systematic errors will cancel out in the average.
C. Yes, because the average of many measurements is always equal to the true value.
D. No, because measurements that have systematic errors cannot be averaged.
For the distribution described below, complete parts (a) and (b) below.
The annual incomes of all those in a statistics class, including the instructor
a. How many modes are expected for the distribution?
A. The distribution is probably bimodal.
B. The distribution is probably uniform.
C. The distribution is probably trimodal.
D. The distribution is probably unimodal.
b. Is the distribution expected to be symmetric, left-skewed, or right-skewed?
A. The distribution is probably right-skewed.
B. The distribution is probably symmetric.
C. The distribution is probably left-skewed.
D. None of these descriptions probably describe the distribution.
For the data described below, identify the level of measurement as nominal, ordinal, interval, or ratio. The postal codes of regions The postal codes of regions
Choose the correct answer below.
ratio lordinal
interval nominal
Last year's budget for the legislative branch of a certain government was $4926 million, and this year it is
$5316 million. Consider last year's budget of $4926 million to be the reference value. Complete parts (a) through (d) below.
a. What is the absolute change in the budget from last year to this year? The absolute change in the budget from last year to this year is
$ 390 million.
(Type an integer or a decimal.)
b. What is the relative change in the budget from last year to this year? The relative change in the budget from last year to this year is
7.9%.
(Round to one decimal place as needed.)
c. Next year's budget is estimated to be $5194million. What is the percentage decrease from this year's budget of $5316 million?
The percentage decrease is
2.3%.
(Round to one decimal place as needed.)
d. If next year's budget is changed so that it is 88% less than this year's budget of $5316 million, what is the amount of next year's budget?
The amount of next year's budget is
$ million.
4890.72
(Type an integer or a decimal.)
Assume that a statistics professor has a height of exactly 185.3 cm. Assume that this height is measured with a tape measure that can be read to the nearest mm (or 1/10 cm) and results from two different measurements are reported as 185 cm and 186.0 cm. Which measurement is more precise? Which is more accurate? Explain.
Identify which measurement is more precise, and explain why.
A. The measurement of 186.0 cm is more precise, because it has more decimal places.
B. The measurement of 186.0 cm is more precise, because it is nearer to the true value.
C. The measurement of 186.0 cm is more precise, because it uses a better measurement method.
D. The measurement of 185 cm is more precise, because it is nearer to the true value.
E. The measurement of 185 cm is more precise, because it uses a better measurement method. Identify which measurement is more accurate, and explain why.
A. The measurement of 185 cm is more accurate, because it is nearer to the true value.
B. The measurement of 186 cm is more accurate, because it is nearer to the true value.
C. The measurement of 185 cm is more accurate, because it uses a better measurement method.
D. The measurement of 186.0 cm is more accurate, because it has more decimal places.
E. The measurement of 186.0 cm is more accurate, because it uses a better measurement method.
Consider a distribution of the weights of cars in the new car lot at a car dealership in which about half the inventory consists of compact cars and the other half consists of sport utility vehicles.
How many modes would you expect for the distribution? Would you expect the distribution to be symmetric, left-skewed, or right-skewed?
Choose the correct answer below. A.One mode; symmetric
B. Two modes; right-skewed
C. One mode; right-skewed
D. Two modes; symmetric
The accompanying histogram shows the time until failure for a sample of 203 computer chips. Classify the distribution according to its number of modes and its symmetry or skewness. In words, summarize the meaning of your results.
Click on the icon to view the histogram.
Classify the distribution. Choose the correct answer below. A.The distribution is bimodal and right-skewed.
B. The distribution is unimodal and right-skewed.
C. The distribution is unimodal and left-skewed.
D. The distribution is trimodal and right-skewed.
E. The distribution is bimodal and left-skewed.
F. The distribution is trimodal and left-skewed.
Summarize the meaning of the results. Choose the correct answer below.
A. Most computer chips fail in the twelfth month of operation, and increasing numbers of chips
fail in the months leading up to that point.
B. Most computer chips fail in the seventh, fifth, and twelfth months of operation, and increasing numbers of chips fail as the months progress.
C. Most computer chips fail in the first month of operation, and decreasing numbers of chips fail in the following months.
D. Most computer chips fail in the first and seventh months of operation, and decreasing numbers of chips fail as the months progress.
The accompanying graph shows the minimum wage in a certain country, together with its purchasing power, which is adjusted for inflation with 1996 used as the reference year. The graph represents the years from 1955 to 2011. Summarize what the graph shows.
Click on the icon to view the graph. What does the graph show?
A. The minimum wage has steadily decreased since 1955. The purchasing power of the minimum wage increased until the late 1960s, then decreased until the late 1980s, and has been relatively stable in recent years.
B. The minimum wage has steadily increased since 1955. The purchasing power of the minimum wage increased until the late 1960s, then decreased until the late 1980s, and has been relatively stable in recent years.
C. The minimum wage has steadily increased since 1955. The purchasing power of the minimum wage decreased until the late 1960s, then increased until the late 1980s, and has been relatively stable in recent years.
D. The minimum wage has steadily decreased since 1955. The purchasing power of the minimum wage decreased until the late 1960s, then increased until the late 1980s, and has been relatively stable in recent years.
E. Due to misleading factors, the graph does not show any useful information.
In a Gallup poll of 1,046 randomly selected adult Americans, 89% said that cloning of humans should not be allowed.
Identify the sample, population, and sampling method. Then comment on whether you think it is likely that the sample is representative of the population.
Identify the sample. Choose the correct answer below. A.89% of randomly selected adult Americans
B. all adult Americans
C. adult people of the whole world
D. the 1,046 randomly selected adult Americans
Identify the population. Choose the correct answer below. A.the 1,046 randomly selected adult Americans
B.adult people of the whole world
C.89% of randomly selected adult Americans D.all adult Americans
This is the correct answer.
Identify the sampling method. Choose the correct answer below. A.Systematic
B.Random C.Convenience
Comment on whether you think it is likely that the sample is representative of the population. Choose the correct answer below.
A. The sample is fairly large and random. Assuming it was obtained by a reputable firm, the sample is likely to be representative of the population.
B. The size of the sample is not equal to the size of the population, so the sample is likely to be representative of the population.
C. The members of the sample have different characteristics than members of the population, so the sample is not likely to be representative of the population.
A survey was conducted to determine how employees found their jobs. The accompanying table and Pareto chart give the successful methods identified by 400 randomly selected employees. Construct a pie chart for these data. Compare the pie chart to the Pareto chart. Can you determine which graph is more effective in showing the relative importance of job sources?
Click on the icon to view the survey results. Click on the icon to view the Pareto chart.
Choose the correct pie chart below.
A key shows that colors repres ent labels as follows: green, "Help-want ed ads"; blue, "Executive search firms"; red, "Networking"; yellow, "Mass mailing."
A.A pie chart contains four sectors with colors and labels as follows: red, 77%; yellow, 12%; blue, 10%; green, 1%. Each sector's size corresponds with its label.1%10%77%12%
B.
A pie chart contains four sectors with colors and labels as follows: green, 61%; red, 20%; yellow, 14%; blue, 6%. Each sector's size corresponds with its label.61%6%20%14%
C.
A pie chart contains four sectors with colors and labels as follows: blue, 61%; yellow, 20%; red, 14%; green, 6%. Each sector's size corresponds with its label.6%61%14%20%
D.
A pie chart contains four sectors with colors and labels as follows: red, 61%; green, 20%; blue, 14%; yellow, 6%. Each sector's size corresponds with its label.20%14%61%6% This is the correct answer.
Is the Pareto chart or the pie chart more effective in showing the relative importance of job sources?
A.
The pie chart is more effective in showing the relative importance of job sources, because the wedges in a pie chart represent the relative frequencies while the bars in a Pareto chart are unrelated to the importance of job sources.
B.
The Pareto chart is more effective in showing the relative importance of job sources by using a vertical scale and arranging the bars in descending order.
This is the correct answer.
C.
The pie chart is more effective in showing the relative importance of job sources, because Pareto charts should only be used with relative frequencies.
D.
The Pareto chart is more effective in showing the relative importance of job sources because the heights of the bars in the Pareto chart represent frequencies while the wedges in a pie chart are unrelated to the importance of job sources.
E.
Neither chart is effective in showing the relative importance of job sources.
A professor records the following final grades in one course. Construct a frequency table for the grades. A A A A A A A B B B B B B C
C C CC C C C C D D D D D D F F
Complete the table.
(Type an integer or decimal rounded to the nearest tenth as needed.)
GradeFrequency Relative frequency Cumulative frequency
A
D F
Total
24
%
%
%
1
1equals=100%
The numbers of words defined on randomly selected pages from a dictionary are shown below. Find the mean, median, and mode of the listed numbers.
77 79 71 54 76 73 56 65 46 50
What is the mean? Select the correct choice below and, if necessary, fill in the answer box within your choice.
A. The mean is 64.7. (Round to one decimal place as needed.)
B. There is no mean.
What is the median? Select the correct choice below and, if necessary, fill in the answer box within your choice.
A. The median is 68.0. (Round to one decimal place as needed.)
B. There is no median.
What is(are) the mode(s)? Select the correct choice below and, if necessary, fill in the answer box within your choice.
A. The mode(s) is(are) nothing. (Round to one decimal place as needed. Use a comma to separate answers as needed.)
B. There is no mode.
What is a placebo, and why is it important in an experiment to test the effectiveness of a drug? What is a placebo?
A.A placebo refers to a situation in which a patient improves simply because they believe they are receiving a useful treatment.
B.A placebo is physically similar to a treatment, but it lacks any active ingredients, so it should not by itself produce any effects.
C.A placebo refers to a specific member of a sample from which data are collected.
D.A placebo refers to any problem in the design or conduct of a statistical study that tends to favor certain results.
Why is it important in an experiment to test the effectiveness of a drug?
A.A placebo exaggerates any psychological differences between the control group and the treatment group.
B.A placebo makes the sample more representative of the population.
C.A placebo is important so that results from subjects given a treatment can be compared with the results from subjects given a placebo.
D.A placebo makes the sample less representative of the population but the data can still be used to make inferences about the population.
Suppose that a polygraph is 90% accurate (it will correctly detect 90% of people who are lying and it will correctly detect 90% of people who are telling the truth). The 1,950 employees of a company are given a polygraph test during which they are asked whether they use drugs. Assume that anyone whom the polygraph operator finds untruthful is accused of lying. Complete parts (a) and (b).
UsersNonusers Total Test finds employee lying 1818 193193 211211
Test finds employee truthful 22 1 comma 7371,7371 comma 7391,739
Total 2020 1 comma 9301,9301 comma 9501,950
a. How many employees are accused of lying?
How many employees accused of lying were actually lying?
18
How many employees accused of lying were telling the truth?
What percentage of those accused of lying were falsely accused?
%
(Round to the nearest tenth as needed.)
b. How many employees are found truthful?
How many employees that are found truthful were actually truthful?
What percentage of those found truthful really were truthful?
%
(Round to the nearest tenth as needed.)
An article noted that chocolate is rich in flavonoids. The article reports that "regular consumption of foods rich in flavonoids may reduce the risk of coronary heart disease." The study received funding from a candy company and a chocolate manufacturers association. Identify and explain
at least one source of bias in the study described. Then suggest how the bias might have been avoided.
Choose the correct answer below.
A.
The data do not seem to support the claims being made by the article. The article's author should consult an expert to make sure that he or she is correctly interpreting the study's results.
B.
The questions used in the study might have caused the respondents to give inaccurate or dishonest responses. The question wording should be changed to be more neutral.
C.
The researchers may have been more inclined to provide favorable results because funding was provided by a party with a definite interest. The bias could have been avoided if the researchers were not paid by the candy company and the chocolate manufacturers.
This is the correct answer. D.
Since the sample is self-selected, there is a definite participation bias in this study. The researchers should randomly select the subjects of the study.
The following histogram depicts cotinine levels (in milligrams per milliliter) of a sample of subjects who smoke cigarettes. Cotinine is a metabolite of nicotine, which means that cotinine is produced by the body when nicotine is absorbed.
Cotinine levels
-20002004006000816sample valueNumber of subjects8912103
•
•
•
A histogram is titled “Cotinine levels.” Its horizontal axis is labeled “sample value” from negative 200 to 600 in increments of 200 and its vertical axis is labeled “Number of subjects” from 0 to 16 in increments of 1. The heights of the vertical bars of bin width 100 are as follows: negative 150 to negative 50, 0; negative 50 to 50, 8; 50 to 150, 9; 150 to
250, 12; 250 to 350, 10; 350 to 450, 0; 450 to 550, 3.
a. How many subjects are represented in the histogram?
42 (Simplify your answer.)
b. How many subjects have cotinine levels below 400?
39 (Simplify your answer.)
c. How many subjects have cotinine levels above 150?
25 (Simplify your answer.)
d. What is the highest possible cotinine level of a subject represented in this histogram?
550
(Type a whole number.)
To estimate the percentage of defects in a recent manufacturing batch, a quality control manager at Apple selects every 16th ipod that comes off the assembly line starting with the fifth until she obtains a sample of 70 ipods.
What type of sampling is used? A.Simple random
B.Stratified C.Convenience D.Cluster E.Systematic
In a survey of 1,377 office workers, 4.24.2% said that they do not make personal phone calls. Find the actual number of respondents corresponding to the given percentage.
The number of office workers who said that they do not make personal phone calls is
58.
(Round to the nearest integer as needed.)
Cluster sampling and stratified sampling both involve selecting subjects in subgroups of the population. What is the difference between those two types of sampling?
Choose the correct answer below.
A.With cluster sampling, one member of the population is selected from each of the subgroups (or clusters), but with stratified sampling, more than one member of the population is selected from each of the subgroups (or strata).
B.With cluster sampling, all members of randomly selected subgroups (or clusters) are selected, but with stratified sampling, samples from each of the different subgroups (or strata) are selected. C.With cluster sampling, samples from each of the different subgroups (or clusters) are selected, but with stratified sampling, all members of randomly selected subgroups (or strata) are selected. D.There is no difference between cluster and stratified sampling.
For the data described below, identify the level of measurement as nominal, ordinal, interval, or ratio. The sizes of coffee offered by a coffee shop left parenthesis small comma medium comma large right parenthesisThe sizes of coffee offered by a coffee shop (small, medium, large)
Choose the correct answer below.
ordinal nominal
ratio interval
Decide whether the following statement makes sense (or is clearly true) or does not make sense (or is clearly false). Explain your reasoning.
My experiment proved beyond a doubt that vitamin C can reduce the severity of colds, because I controlled the experiment carefully for every possible confounding variable.
Choose the correct answer below.
A. The statement makes sense because confounding variables are the only reason an experiment's results could be doubted.
B. The statement does not make sense because it is not always easy to discover confounding variables.
C. The statement does not make sense because confounding variables would not affect the reliability of the experiment.
D. The statement makes sense because every possible confounding variable can be eliminated through careful study.
A company hires independent university scientists to determine whether its new, genetically engineered soybean poses any threat to the environment.
Are there sources of bias in this situation? Choose the correct answer below.
A. There does appear to be sources of bias.
B. There do not appear to be any sources of bias.
One of the authors received a credit card bill for $2 comma 5672,567, but it included a charge of $ 1 comma 659$1,659 that was not valid. Find the values of the absolute and relative errors.
The value of the absolute error is
$ 1,659.
The value of the relative error is
183%.
(Round to the nearest integer as needed)
A psychologist has developed a procedure for modifying behavior so that subjects suffering from depression can greatly improve that condition. In formal tests of the effectiveness of the treatment, what is an experimenter effect, and how might it be avoided?
In formal tests of the effectiveness of the treatment, what is an experimenter effect?
A.
An experimenter effect is when the researchers performing the effectiveness study know which subjects are in the control group and which subjects are in the treatment group. This knowledge allows the
researchers to avoid influencing the results by behaving differently toward the subjects in the different groups.
B.
An experimenter effect is when the subjects of the study are aware of whether or not they are receiving the treatment and this influences the results of the study.
C.
An experimenter effect is when the researchers performing the effectiveness study know which subjects are in the control group and which are in the treatment group. This knowledge influences the results of the study through differences in the behavior of the researchers toward the subjects in the different groups.
This is the correct answer.
D.
An experimenter effect is when the researchers performing the effectiveness study are also subjects in the study and their participation influences the results of the study.
How might it be avoided?
A.
The researchers should be informed who is in the treatment group and who is in the control group.
B.
The researchers should not be allowed to know who is in the treatment group and who is in the control group.
This is the correct answer.
C.
The study participants should be informed who is in the treatment group and who is in the control group.
D.
The study participants should not be allowed to know who is in the treatment group and who is in the control group.
What is the distinction between qualitative data and quantitative data? Give a few examples of each. Choose the correct answer below.
A.
Quantitative data describe categories, while qualitative data represent counts or measures. Brand names of shoes in a consumer survey and eye colors are examples of quantitative data. Heights of students and quiz scores are examples of qualitative data.
B.
Quantitative data describe categories, while qualitative data represent counts or measures. Brand names of shoes in a consumer survey and eye colors are examples of qualitative data. Heights of students and quiz scores are examples of quantitative data.
C.
Qualitative data describe categories, while quantitative data represent counts or measures. Brand names of shoes in a consumer survey and eye colors are examples of quantitative data. Heights of students and quiz scores are examples of qualitative data.
D.
Qualitative data describe categories, while quantitative data represent counts or measures. Brand names of shoes in a consumer survey and eye colors are examples of qualitative data. Heights of students and quiz scores are examples of quantitative data.
This is the correct answer.
The temperatures left parenthesis in degrees Upper C right parenthesis of water samples taken simultaneously in a large lake temperatures (in °C) of water samples taken simultaneously in a large lake are shown below.
23.1 22.1 24.4 23.4 20.5 19.3 19.3 19.2 22.8
Determine whether the data are qualitative or quantitative and identify the data set's level of measurement.
Are the data qualitative or quantitative? Qualitative
Quantitative
What is the data set's level of measurement? Ordinal
Interval Nominal Ratio
The accompanying figure depicts the populations for three regions (A, B, and C). How is this graph misleading? How could it be drawn so that it is not misleading?
Click the icon to view the figure. How is the graph misleading?
A. The graph is misleading because the horizontal axis scale does not start at zero.
B. The graph is misleading because it does not use a uniform scale for the horizontal axis.
C. The graph is misleading because the length of each bar is proportional to the population of each region, but the area of each bar is proportional to the square of each region's population. D.The graph is misleading because the population for each region is given in different units. How could the graph be drawn so that it is not misleading?
A. By using a linear scale on the horizontal axis, the graph will not be misleading.
B. By giving the population of each region in the same units, the graph will not be misleading.
C. By keeping the height of each bar in the graph constant while their lengths vary, the area of each bar will be proportional to the population of each region and the graph will not be misleading.
D. By starting the horizontal scale at 0, the graph will not be misleading.
Blood alcohol concentrations of drivers involved in fatal crashes and then given jail sentences are listed below. Find the range and standard deviation.
0.25 0.18 0.18 0.16 0.13 0.23
0.29 0.23 0.14 0.16 0.12 0.16
Find the range.
rangeequals= 0.170 Find the standard deviation.
sequals= 0.053
(Round to the nearest thousandth as needed.) [Show Less]