AP Statistics Review

The histogram pictured here 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?

• 2.50

• 7.25

• 12.25

• 15.00

• 17.50

Correlation coefficient, r, does not depend on the units of measurement of the two variables.

• True

• False

If r = 1 , the standard deviation of y is equal to the standard deviation of the residuals.

• True

• False

The standard deviation about the least squares line is roughly the typical amount by which an observation deviates from the least squares line.

• True

• False

Two events are said to be disjoint or mutually exclusive when they have no outcomes in common.

• True

• False

For a continuous random variable x, the height of the density curve over an interval a to b represents the probability that x is between a and b.

• True

• False

Answer explanation

Area under the curve is the probability not the height

One disadvantage of using the mean as a measure of center for a data set is that its value is affected by the presence of even a single outlier in the data set.

• True

• False

Which statistic can not be determined from a box plot representing the scores on a math test in Mrs. DeRidder’s algebra class?

• the lowest score

• the median score

• the highest score

• the score that occurs most frequently

The dot plot shown below represents the number of pets owned by students in a class.

Which statement about the data is not true?

• The median is 3.

• The interquartile range is 2.

• The mean is 3.

• The data contain no outliers.

The table below shows the annual salaries for the 24 members of a professional sports team in terms of millions of dollars. The team signs an additional player to a contract worth 10 million dollars per year. Which statement about the median and mean is true?

• Both will increase.

• Only the median will increase.

• Only the mean will increase.

• Neither will change.