AP Statistics Review

The scores on a university examination are Normally distributed with a mean of 62 and a standard deviation of 11. If the bottom 5% of students will fail the course, what is the lowest mark that a student can have and still be awarded a passing grade?

• 40

• 43

• 44

• 57

• 62

At Central High School, 28% of the students are Freshmen, 26% are Sophomores, 24% are Juniors, and 22% are Seniors. The student manager of the school newspaper would like to conduct a survey to estimate the proportion of each class that plans to attend the upcoming Football game. She suggests surveying a random sample of 100 students, but specifically by selecting random samples of 28 Freshmen, 26 Sophomores, 24 Juniors, and 22 Seniors. Which of the following is a true statement about this sampling procedure?

• This is a simple random sample because students of every class have an equal chance of being selected.

• This is a cluster random sample because there are 4 groups of students that are to be selected.

• This is a convenience sample because only 100 students are surveyed, which is a manageable size.

• This is a stratified random sample because a separate random sample is selected from each class.

• Yes, because the difference between the sample proportion and the population proportion is 0.04, which is less than 0.05.

How do I find the Interquartile Range (IQR) on a box plot?

• Add the min. and max.

• Add Q1 and Q3

• Subtract Q1 from Q3

• Subtract the min. from the max.

What is the total area under the normal curve in a standard Normal distribution?

• 1

• 2

• 3

• 4

• A

• B

• C

• D

• E

Is this a probability distribution?

• No, the sum of p(x) does not equal 1.

• Yes, all p(x) are between 0 and 1.

• No, all p(x) are not between 0 and 1.

• Yes, the sum p(x) is 1.

Is this a probability distribution?

• No

• Yes

Two measures of center are marked on the density curve shown. Which of the following is correct?

• 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.

A z-score tells you...

• the standard deviation of a sampling distribution.

• the original raw score on which it is based.

• if the distribution it comes from is normal.

• how many standard deviations away from the mean a score lies.

If Gonzalo's score is 87, the class average is 82, and the SD is 4, what is Gonzalo's Z-score?

• -1.25

• +1.25

• +1.20

• +1.02