Chapter 4 AP Stats Review

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 point in the upper right hand corner of the scatterplot is

• not an outlier or an influential point

• not an outlier but an influential point

• an outlier and an influential point

• an outlier but not an influential point

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.

The weights of cockroaches living in a university dormitory follow a Normal distribution with mean 80 grams and standard deviation 5 grams. The percentage of cockroaches having weights between 72 grams and 88 grams must be

• less than 68%.

• between 68% and 95%.

• between 95% and 99.7%.

• between 99.7% and 100%.

Scores on the American College Testing (ACT) college entrance exam follow a Normal distribution with mean 18 and standard deviation 6. Lisa’s standardized score on the ACT was z = -0.7. What was her actual ACT score?

• 4.2

• 13.8

• 17.3

• 22.2

The lifetime of 9-volt battery in constant use has an approximately Normal distribution with a mean of 516 hours and a standard deviation of 20 hours. Which of the following best describes the distribution of standard scores for the lifetimes of such batteries?

• Exactly Normal, with mean 0 and standard deviation 1.

• Approximately Normal, with mean 0 and standard deviation 1.

• Approximately Normal, with mean 1 and standard deviation 1.

In the class of 2016, more than 1.6 million students took the SAT. The distribution of scores on the math section (out of 800) follows an approximately Normal distribution with a mean of 508 and standard deviation of 110. About what percent of students who took the SAT scored less than 350 on the math section?

• about 1.4%

• about 7.5%

• about 12%

We wish to draw a sample of 5 without replacement from a population of 50 households. Suppose the households are numbered 01, 02, . . . , 50, and suppose that the relevant line of the random number table is 11362 35692 96237 90842 46843 62719 64049 17823. Then the households selected are

• households 11 13 36 62 73

• households 11 36 23 08 42

• households 11 36 23 23 08

• households 11 36 23 56 92

• households 11 35 96 90 46

A maple sugar manufacturer wants to estimate the average trunk diameter of Sugar Maples trees in a large forest. There are too many trees to list them all and take a SRS, so he divides the forest into several hundred 10 meter by 10 meter plots, selects 25 plots at random, and measures the diameter of every Sugar Maple in each one. This is an example of a

• multistage sample.

• stratified sample

• simple random sample.

• cluster sample.

• convenience sample.

A least-squares regression line for predicting weights of basketball players on the basis of their heights produced the residual plot below. What does the residual plot tell you about the linear model?

• A residual plot is not an appropriate means for evaluating a linear model.

• The curved pattern in the residual plot suggests that there is no association between the weight and height of basketball players.

• The curved pattern in the residual plot suggests that the linear model is not appropriate.

• There are not enough data points to draw any conclusions from the residual plot.

• The linear model is appropriate, because there are approximately the same number of points above and below the horizontal line in the residual plot.