AP Stats Unit 2 Practice

• A

• B

• C

• D

• E

• A

• B

• C

• D

• E

The cumulative relative frequency graph below describes the distribution of weights (in grams) of tomatoes grown in a laboratory experiment. Which of the following weights is closest to the median of the distribution?

• 120 gm

• 140 gm

• 160 gm

• 170 gm

The dot plot shows the voter turnout (as a percentage of voting-age population) for the 50 states—plus the District of Columbia—in a recent presidential election. Approximately what percentage had a turnout above 65%?

• 27.5%

• 17.6%

• 18%

Which of the following are properties of all normal distributions?

• Mean = Median = 1

• There is no data above 3 SD away from the mean

• The distribution is symmetric

• The Empirical Rule is always applicable

• The distribution is sometimes bimodal

A standard normal distribution:

• Always has a standard deviation of 1

• Is bell-shaped

• 95% of the data lies within 2 standard deviations of the mean

• Has a mean and median of 0

• All of the above

What fraction of the terms in a normal distribution have z-scores between -1.5 and 2.2?

• 0.8787

• 0.4861

• 0.9193

• 0.0529

What is the standard deviation of a normal distribution, whose mean is 22, in which an x-value of 36 has a z-score of 3.11?

• 4.5

• -4.5

• 1.495

• 0.523

Suppose you have a distribution that is approximately normal with a mean of 25 and a standard deviation of 1.4. If we were to replace each data point with its standardized value, what would the new mean and standard deviation be?

• 25 and 1.4

• 0 and 1

• 1 and 0

• Not enough information

Consider a normal distribution that has N(63,9) (that is, a mean of 63 and a standard deviation of 9). To the nearest integer, the percentile rank of a value of 50 in this distribution is:

• 7

• 20

• 16

• 93