MATH 225N WEEK 8 FINAL EXAM QUESTIONS AND
ANSWERS LATEST UPDATES ALREADY PASSED
Question 1
Data is collected on the relationship between time spent
... [Show More] playing video games and time s pent with
family. The data is shown in the table and the line of best fit for the data is y^=−0.27x+57.5.
Assume the line of best fit is significant and there is a strong linear relationship between the
variables.
According to the line of best fit, the predicted number of minutes spent with family for someone
who spent 95 minutes playing video games is 31.85. Is it reasonable to use this line of best fit to
make the above prediction?
Ans:
The estimate, a predicted time of 31.85 minutes, is unreliable but reasonable.
The estimate, a predicted time of 31.85 minutes, is both unreliable and unreasonable.
The estimate, a predicted time of 31.85 minutes, is both reliable and reasonable.
The estimate, a predicted time of 31.85 minutes, is reliable but unreasonable.
Question 2
Which of the following are feasible equations of a least squares regression line for the annual
population change of a small country from the year 2000 to the year 2015? Select all that apply.
Ans:
yˆ=38,000+2500x
yˆ=38,000−3500x
yˆ=−38,000+2500x
yˆ=38,000−1500x
Question 3
To test the effectiveness of a drug proposed to relieve symptoms of headache, physicians
included participants for a study. They gave the drug to one group and a drug with no therapeutic
effect to another group. Which group receives the placebo?
Ans:
the physicians
the group that received the drug for headache
the group that received the drug with no therapeutic effect
all of the people in the study
Question 4
Becky's statistics teacher was teaching the class how to perform the z-test for a proportion.
Becky was bored because she had already mastered the test, so she decided to see if the coin s he
had in her pocket would come up heads or tails in a truly random fashion when flipped. She
discretely flipped the coin 30 times and got heads 18 times.
Becky conducts a one-proportion hypothesis test at the 5% significance level, to test whether the
true proportion of heads is different from 50%.
Which answer choice shows the correct null and alternative hypotheses for this test?
Ans:
H0:p=0.6; Ha:p>0.6, which is a right-tailed test.
H0:p=0.5; Ha:p<0.5, which is a left-tailed test.
H0:p=0.6; Ha:p≠0.6, which is a two-tailed test.
H0:p=0.5; Ha:p≠0.5, which is a two-tailed test.
Question 5
A farmer divided his piece of land into 4 equivalent groups. The quality of the soil is the same
across the 4 groups of land. He planted the same crop in all 4 groups of land and recorded the
yield of the crop in all 4 groups for a 4 week period. Is the study observational or experimental?
If it is an experiment, what is the controlled factor?
Ans:
The study is an observational study.
The study is an experiment. The controlled factor is the 4 w eek observation period.
The study is an experiment. The controlled factor is the land.
The study is an experiment. The controlled factor is the growth of the crops.
Question 6
The population standard deviation for the heights of dogs, in inches, in a city is 3.7 inches. If we
want to be 95% confident that the sample mean is within 2 inches of the true population mean,
what is the minimum sample size that can be taken?
Use the table above for the z-score, and be sure to round up to the nearest integer.
Ans: 14 dog heights
Question 7
Assume the null hypothesis, H0, is: Jacob earns enough money to afford a luxury apartment.
Find the Type I error in this scenario.
Ans:
Jacob thinks he does not earn enough money to afford the luxury apartment when, in fact,
he does.
Jacob thinks he does not earn enough money to afford the luxury apartment when, in fact, he
does not.
Jacob thinks he earns enough money to afford the luxury apartment when, in fact, he does not.
Jacob thinks he earns enough money to afford the luxury apartment when, in fact, he does.
Question 8
The graph below shows the graphs of several normal distributions, labeled A, B, and C, on the
same axis. Determine which normal distribution has the smallest standard deviation.
Ans: B
Question 9
A doctor notes her patient's temperature in degrees Fahrenheit every hour to make sure the
patient does not get a fever. What is the level of measurement of the data?
Ans:
Nominal
ordinal
Interval
ratio
Question 10
Given the following list of prices (in thousands of dollars) of ran [Show Less]