Chapter 8 AP Stats

• The median is at the yellow line and the mean is at the red line

• The median is at the red line and the mean is at the yellow line

• The mode is at the red line and the median is at the yellow line

• The mode is at the yellow line and the median is at the red line

• The mode is at the red line and the mean is at the yellow line

The weights of laboratory cockroaches follow a Normal distribution with mean 80 grams and standard deviation 2 grams. The following figure is the Normal curve for the distribution of weights. Point C on this Normal curve corresponds to

• 84 grams

• 82 grams

• 78 grams

• 76 grams

• 74 grams

The weights of laboratory cockroaches follow a Normal distribution with mean 80 grams and standard deviation 2 grams. The following figure is the Normal curve for the distribution of weights. About what percent of the cockroaches have weights between 76 and 84 grams?

• 99.7%

• 95%

• 68%

• 47.5%

• 34%

• Pete's score was below the median.

• Pete did worse than about 63% of the test takers.

• Pete did worse than about 73% of the test takers.

• Pete did better than about 63% of the test takers.

• Pete did better than about 73% of the test takers.

The EPA requires that the exhaust of each model of motor vehicle be tested for the level of several pollutants. The level of oxides of nitrogen (NOX) in the exhaust of one light truck model was found to vary among individual trucks according to an approximately Normal distribution with mean μ = 1.45 grams per mile driven and standard deviation σ = 0.40 gram per mile. Which of the following best estimates the proportion of light trucks of this model with NOX levels greater than 2 grams per mile?

• 0.0228

• 0.0846

• 0.4256

• 0.9154

• 0.9772

Which of the following is not correct about a standard Normal distribution?

• The proportion of scores that satisfy 0 < z < 1.5 is 0.4332.

• The proportion of scores that satisfy z < -1.0 is 0.1587

• The proportion of scores that satisfy z > 2.0 is 0.0228

• The proportion of scores that satisfy z < 1.5 is 0.9332

• The proportion of scores that satisfy z > -3.0 is 0.9938

Jorge's score on Exam 1 in his statistics class was at the 64th percentile of the scores for all students. His score falls

• between the minimum and first quartile

• between the first quartile and the median

• between the median and the third quartile

• between the third quartile and the maximum

• at the mean score for all students

When Sam goes to a restaurant, he always tips the server $2 plus $10% of the cost of the meal. If Sam's distribution of meal costs has a mean of $9 and a standard deviation of $3, what are the mean and standard deviation of his tip distribution?

• $2.90, $0.30

• $2.90, $2.30

• $9.00, $3.00

• $11.00, $2.00

• $2.00, $0.90

Scores on the ACT college entrance exam follow a bell-shaped distribution with mean 21 and standard deviation 5. Wayne's standardized score on the ACT was -0.6. What was Wayne's actual ACT score?

• 3

• 13

• 16

• 18

• 24

The number of absences during fall semester was recorded for each student in a large elementary school. The distribution of absences is displayed in the following cumulative relative frequency graph. What is the IQR for the distribution of absences?

• 1

• 2

• 3

• 5

• 1