Sukie interviewed 125 employees at her company and discovered that 21 of them planned to take an extended vacation next year. She finds that the
... [Show More] proportion of people taking extended vacations nationally is 15%.
The z statistic for this data is .
-0.56
-0.45
0.56
0.45
Jesse takes two data points from the weight and feed cost data set to calculate a slope, or average rate of change. A rat weighs 3.5 pounds and costs $4.50 per week to feed, while a Beagle weighs 30 pounds and costs $9.20 per week to feed.
Using weight as the explanatory variable, what is the slope of the line between these two points? Answer choices are rounded to the nearest hundredth.
$0.31 / lb.
$1.60 / lb.
$5.64 / lb.
$0.18 / lb.
A research team conducts a survey to determine the area of land used for farming in Iowa. The team randomly selects house addresses and sends the survey by mail.
Which type of sampling method is the research team using?
Simple random sampling
Systematic random sampling
Multi-stage sampling
Cluster sampling
Katherine, Jonathan, and Ryan went bowling. Afterwards, two of them decided to make bar graphs to plot their scores.
Who made Graph 2, and why?
Jonathan, because he wanted to make the scores appear reasonably close.
Katherine, because she wanted to make the scores appear reasonably close.
Katherine, because she wanted to accurately show each person's score.
Jonathan, because he wanted to make the scores appear very different.
Which of the following is an example of a false positive?
Test results indicate that a patient has cancer when, in fact, he does not.
Test results indicate that a patient does not have cancer when, in fact, he does.
Test results confirm that a patient does not have cancer.
Test results confirm that a patient has cancer.
Jessica uses a poorly calibrated stopwatch to note the finish time of a relay race. She noted the time as 125 seconds, whereas the actual time taken was 120 seconds.
The percent error in Jessica's calculation is .
-4.2%
4.0%
4.2%
-4.0%
Researchers want to study the effects of classical music and memory. One group of participants will take a memory test with classical music playing in the background, while the other group will take the memory test in complete silence. It is believed that age has an effect on memory.
Which of the following would work best to test if classical music has an effect on memory?
A completely randomized design experiment
A randomized block design experiment
A matched-pair design experiment
A case-control observational study
Which of the following is a property of binomial distributions?
The expected value is equal to the number of successes in the experiment.
There are exactly three possible outcomes for each trial.
All trials are dependent.
The sum of the probabilities of successes and failures is always 1.
For a math assignment, Jane has to roll a set of six standard dice and record the results of each trial. She wonders how many different outcomes are possible after rolling all six dice.
What is the total number of possible outcomes for each trial?
216
7,776
46,656
36
Adam tabulated the values for the average speed on each day of his road trip as 60.5, 63.2, 54.7, 51.6, 72.3, 70.7, 67.2, and 65.4 mph.
If Adam wanted to construct a one-sample t-statistic, what would the value for the degrees of freedom be?
7
8
9
4
Which of the following situations describes a continuous distribution?
A probability distribution showing the number of vaccines given to babies during their first year of life
A probability distribution showing the average number of days mothers spent in the hospital
A probability distribution showing the weights of newborns
A probability distribution showing the amount of births in a hospital in a month
What is the p-value of the test statistic? Answer choices are rounded to the thousandths place.
0.134
0.147
0.055
0.067
Ryan, a baker, measured the weights of cakes baked in each batch at his bakery and found that the mean weight of each cake is 500 grams. He performed a hypothesis test to find the mean weight of each cake by setting and .
Select the statement that indicates a Type I error.
Failing to reject the mean weight of each cake as 500 grams when . Rejecting the mean weight of each cake as 500 grams when .
Failing to reject the mean weight of each cake as 500 grams when . Rejecting the mean weight of each cake as 500 grams when .
A study in which results are measured without intervention from the researcher is called a(n) .
Observational study
Simple random sample
Controlled experiment
Pilot study
What is the z-score of the sale of mobile phones on that day?
28
1.75
-28
-1.75
One week, Rachel earned $250. She spent $120 on food, $30 on miscellaneous items, and saved the rest.
If Rachel makes a pie chart showing how she spends her money, the central angle for the food sector would be .
187°
90°
144°
173°
The difference between the standard deviation and the variance of a standard normal distribution is
.
1
2
0.5
0
One condition for performing a hypothesis test is that the observations are independent. Mark is going to take a sample from a population of 400 students.
How many students will Mark have to sample without replacement to treat the observations as independent?
40
300
80
360
This chart shows the number of students of different age groups who participated in a quiz.
Which of the following statements about the stack plot is true?
There were more students in the age group 15-17 than in any other age group.
There were more male students in the age group 19-21 than in the age group 15-17.
There were more male students than female students in the age group 19-21.
There were more female students in the age group 17-19 than in any other age group. [Show Less]