Take this Quiz: AP Statistics — the four big ideas | Zestly

Question 1

A data set of 20 test scores has a mean of 75 and a median of 78. If the highest score is changed from 95 to 150, which of the following best describes the effect on these summary statistics?

Accepted Answer

The mean will increase, but the median will remain unchanged.

Answer

Both the mean and the median will increase significantly.

Answer

The mean will remain unchanged, but the median will increase.

Answer

Both the mean and the median will remain unchanged.

Question 2

A histogram of house prices in a small town shows a long tail extending to the right. Which of the following is the most likely relationship between the mean and the median of these prices?

Accepted Answer

The mean is greater than the median.

Answer

The mean is less than the median.

Answer

The mean is equal to the median.

Answer

The relationship cannot be determined without the sample size.

Question 3

A study finds a correlation coefficient of $r = 0.85$ between the number of hours spent studying and exam scores. Which of the following is a valid conclusion?

Accepted Answer

There is a strong, positive, linear association between studying and scores.

Answer

Studying causes higher exam scores.

Answer

The relationship between studying and scores is perfectly linear.

Answer

An influential point could not possibly exist in this data set.

Question 4

A least-squares regression line for predicting tree height (in metres) from tree age (in years) is given by $\hat{y} = 0.5 + 0.2x$. Which of the following is the correct interpretation of the slope?

Answer

For every 1 metre increase in height, the age increases by 0.2 years.

Answer

The predicted height of a tree at age zero is 0.5 metres.

Answer

The predicted height of a tree increases by 0.5 metres for every year of age.

Answer

For every 1 year increase in age, the predicted height increases by 0.2 metres.

Question 5

A researcher wants to survey students about their cafeteria preferences. They divide the school into grade levels and randomly select 50 students from each grade. What type of sampling method is this?

Answer

Simple random sample

Answer

Stratified random sample

Answer

Cluster sample

Answer

Convenience sample