5 Questions
| Total Attempts: 514

Questions and Answers

- 1.The scatterplot below shows data points and the regression line for predicting y from x. Which statement is true about the effect of removing point A or B on the regression model?
- A.
Removing A would decrease the slope but removing B would increase the slope.

- B.
Removing A would increase the slope but removing B would have little effect on the slope.

- C.
Removing A would decrease the correlation but removing B would increase the correlation.

- D.
Removing point A would increase the correlation and removing point B would not change the correlation.

- E.
Removing point A would increase the y-intercept and removing point B would decrease the y-intercept.

- 2.Which of these statements correctly explains bias?
- A.
It describes a sample that was selected by convenience.

- B.
It describes a lack of randomization in the sampling process.

- C.
It describes a process that results in a sample that does not represent the population.

- D.
It describes a process that creates estimates that are too high on average or too low on average.

- E.
It describes a sample that is not representative of the population.

- 3.A particular crop of one variety of onion has weights that are approximately normally distributed with mean 9.8 oz. and standard deviation 2.1 oz. How does an onion in the 28th percentile for weight compare to the mean?
- A.
1.22 ounces below the mean

- B.
0.59 ounces below the mean

- C.
0.59 ounces above the mean

- D.
1.22 ounces above the mean

- E.
2.26 ounces above the mean

- 4.A pharmaceutical company wants to test a new cholesterol-reducing drug against the previous drug. It does not anticipate much association between cholesterol level and gender, but it does anticipate an association between cholesterol level and the amount of exercise a person gets. For a randomized block design, it should:
- A.
Block on gender because it is not associated with cholesterol level.

- B.
Block on gender because males and females are different.

- C.
Block on the type of drug because it may be associated with cholesterol level.

- D.
Block on exercise level because it is associated with cholesterol level.

- E.
Block on both gender and exercise because blocking on more variables gives more reliable estimates.

- 5.A maker of cereals plans to run a promotion in which an action figure is included in each box of cereal. The more popular figures will appear in fewer boxes. The probability of getting a box with each kind of toy is shown in the table below. What is the probability that the first two randomly selected boxes contain a Serenity and a Redstar toy? Toy Serenity Redstar Spartacus Kropp Probability 0.12 0.18 0.30 0.40
- A.
0.0216

- B.
0.0432

- C.
0.0468

- D.
0.2748

- E.
0.3000