Chapter 5 AP Stats Review

Which of the distributions displayed in the dot plots below has the highest standard deviation?

• Distribution A

• Distribution B

• Distribution C

Which of the following statements about the slope of the least-squares regression line is true? 

• It has the same sign as the correlation coefficient r.

• The square of the slope equals the proportion of the variation in the response variable that is explained by the explanatory variable.

• It is unitless.

• When the x-variable is 0, this is what the y-variable is predicted to be.

One of the following is a correct statement involving correlation. The other three contain blunders. Which one is correct? 

• The correlation between the gas mileage of a car and its weight is r = -0.71 gallon-pounds.

• The correlation between GPA and hours of sleep per night is r = 1.06.

• There is a correlation of r = 0.54 between the position a football player plays and his or her weight.

• The correlation between amount of fertilizer and pounds of tomatoes harvested was found to be r = 0.33.

A study showed that students who spend more time studying for statistics tests tend to achieve better scores on their tests. In fact, the number of hours studied turned out to explain 81% of the observed variation in test scores among the students who participated in the study. What is the value of the correlation between number of hours studied and test score?

• r = 0.81

• r = 0.656

• r = 0.9

• There is no way to know.

If you graphed height as the explanatory variable and weight as the response variable, what would happen to the LSRL and r if you had accidently graphed the weight as the explanatory variable and the height as the response variable?

• LSRL would be different and r would be different

• LSRL would be different and r would stay the same

• LSRL would stay the same and r would be different

• LSRL would stay the same and r would stay the same

The equation of a regression line is y = 0.5x + 35 where x is father’s height in inches and y is son’s height in inches. For a father who is 72 inches tall, what would we predict for the son’s height?

• 69 inches 

• 71 inches 

• 72 inches

• 74 inches

The mean of a distribution that is skewed to the left is smaller than the median.

• True

• False

A set of data with many gaps has a smaller standard deviation than a set of data with a few or no gaps.

• True

• False

The mean weight of an adult female beagle is 28 pounds with a standard deviation of 3 pounds.  The mean weight of an adult female boxer is 70 pounds with a standard deviation of 6 pounds.  A beagle named Suzie weighs 34 pounds.  How much would a female boxer have to weigh in order for her to have the same z-score as Suzie?

• 70 pounds

• 76 pounds

• 80 pounds

• 82 pounds

For the density curve shown, which of the following statements is true?

• The mean is larger than the median.

• The proportion of outcomes between 0.2 and 0.5 is equal to 0.3.

• The total area under the curve is greater than 1.

• The proportion of outcomes greater than 1.5 is equal to 0.25.