AP Stats: Review Through Day 25

Discrete or Continuous:

The height of a player on a basketball team

• Discrete

• Continuous

Discrete or Continuous:

The number of pages in a Statistics textbook

• Discrete

• Continuous

The lengths of pregnancies of humans are normally distributed with a mean of 268 days and a standard deviation of 15 days. Find the probability of a pregnancy lasting less than 250 days.

• 0.1591

• 0.0606

• 0.0066

• 0.1151

The distribution of cholesterol levels in teenage boys is approximately normal with μ = 170 and σ = 30 (Source: U.S. National Center for Health Statistics). Levels above 200 warrant attention. Find the probability that a teenage boy has a cholesterol level greater than 200.

• 0.3419

• 0.2138

• 0.8413

• 0.1587

Compare the scores: a score of 220 on a test with a mean of 200 and a standard deviation of 21 and a score of 90 on a test with a mean of 80 and a standard deviation of 8.

• A score of 90 with a mean of 80 and a standard deviation of 8 is better

• You cannot determine which score is better from the given information.

• A score of 220 with a mean of 200 and a standard deviation of 21 is better.

• The two scores are statistically the same.

Assume that the heights of women are normally distributed with a mean of 64.9 inches and a standard deviation of 1.6 inches. Find the value that separates the bottom 75% from the top 25%.

• 63.8

• 66.0

• 66.9

• 66.7

Assume that the heights of women are normally distributed with a mean of 63.6 inches and a standard deviation of 2.5 inches. If 100 women are randomly selected, find the probability that they have a mean height greater than 60.4 inches.

• 0.8989

• 0.0082

• 0.9918

• 0.2881

The lengths of pregnancies are normally distributed with a mean of 268 days and a standard deviation of 15 days. If 64 women are randomly selected, find the probability that they have a mean pregnancy between 266 days and 278 days.

• 0.2881

• 0.7881

• 0.3577

• 0.3005

In a random sample of 38 families, the average weekly food expense was $95.60 with a standard deviation of $22.50.

• Cannot use normal distribution or t-distribution.

• Use normal distribution.

• Use t-distribution.

A survey of 100 fatal accidents showed that 44 were alcohol related. Find a point estimate for p, the population proportion of accidents that were alcohol related.

• 0.786

• 0.44

• 0.306

• 0.56