AP Statistics

Choose all correct answers:

Measures the number of standard deviations a data value falls above or below the mean.

• Variance

• Standardized Score

• Probability

• Residual

• Z-Score

When the majority of the data is distributed equally across the graph and there are no outliers, the graph is ​​ (a)   u. Therefore the mean is ​ (b)   the median.

• uniform

• equal to

• symmetric

• left-skew

• below

• right-skew

• above

A slice of pizza from a certain restaurant has an average area of 40 square inches with a standard deviation of  5 square inches.  Assuming the distribution of areas is approximately normal, what proportion of slices will be between 35 and 50 square inches

• 68%

• 34%

• 81.5%

• 95%

• A

• B

• C

• D

• E

• A

• B

• C

• D

• E

Some descriptive statistics for a set of test scores are shown above. For this test, a certain student has a standardized score of z = -1.2. What score did this student receive on the test?

• 266.28

• 779.42

• 1008.02

• 1083.38

• 1311.98

The histogram below displays the frequencies of waiting times, in minutes, for 175 patients in a dentist's office.

Which of the following could be the median of the waiting times, in minutes?

• 2.5

• 7.25

• 12.25

• 15

• 17.50

The histogram above shows the number of minutes needed by 45 students to finish playing a computer game.

Which of the following statements is correct?

• The distribution is skewed to the right.

• The distribution is skewed to the left.

• The distribution appears to be normal.

• The distribution appears to be chi-square.

• The distribution appears to be uniform.

Data were collected on the amount, in dollars, that individual customers spent on dinner in an Italian restaurant. The quartiles for these data are given in the picture. Which of the following statements must be true for these customers?

• At least half of the customers spent less than or equal to $44.27 and at least half spent greater than or equal to $44.27.

• Seventy-five percent of the customers spent between $36.27 and $58.97.

• Twenty-five percent of the customers spent less than or equal to $58.97 and the remaining 75 percent spent greater than or equal to $58.97.

• The mean amount spent by customers is $44.27.

• A majority of customers spent $44.27.

The back-to-back stem-and-leaf plot below gives the percentage of students who dropped out of school at each of the 49 high schools in a large metropolitan school district. Which of the following statements is NOT justified by these data?

• The drop-out rate decreased in each of the 49 schools between the 1989-90 and 1992-1993 school years.

• For the school years shown, most students in the 49 schools did not drop out of high school.

• In general drop-out rates decreased between the 1989-90 and 1992-1993 school years.

• The median drop-out rate of the 49 high schools decreased between the 1989-90 and 1992-1993 school years.

• The spread between the schools with the lowest drop-out rates and those with the highest drop-out rates did not change much between the 1989-90 and 1992-1993 school years.