Comparing Data Displays and Distributions

Given a set of skewed data, which is an appropriate measure of spread?

• Mean

• Median

• Standard Deviation

• Interquartile Range (IQR)

Gabriella’s quiz grades are shown below.
88, 92, 92, 96, 98
Gabriella scored a 20 on her sixth quiz. What effect does this score have?

• The low score causes the median to increase.

• The low score causes the median to decrease.

• The low score causes the mean to increase.

• The low score causes the mean to decrease.

The prices at several different stores for a pair of shoes are shown below.
$78, $79, $81, $82, $83
Two days later, another store has the same shoes on sale for $65. How does the new price affect the data?

• Only the range was affected.

• The median increased, and the range increased.

• The mean increased, and the range increased.

• The mean decreased and the range increased.

Two groups, each consisting of 38 high school students, participated in a survey about the number of times they sent a text message during lunch. The frequency tables shown display the results. Choose the best measure of center and variability for comparing the distributions.

• Best measure of center: Median; Best measure of variability: Interquartile Range

• Best measure of center: Median; Best measure of variability: Standard Deviation

• Best measure of center: Mean; Best measure of variability: Interquartile Range

• Best measure of center: Mean; Best measure of variability: Standard Deviation

Which of the following statements can be concluded from the display?

• There were more films under 100 minutes than there were over 100 minutes.

• Most of the films in this data set were more than 105 minutes.

• More films were longer than 110 minutes than were less than 95 minutes.

• It is impossible to determine the total number of films that were analyzed in the

  data.

Two of Mr. Evan’s Earth Science classes have 23 students each. Box plots for the recent test scores for these two classes are displayed. Which of the following statements cannot be determined from the distributions shown on the figure?

• The means of the two sets of data are equal.

• The upper quartile of third period and the upper quartile of fifth period are equal.

• More students in third period scored an 87 or above compared to the fifth period.

• The number of students in third period who scored from 73 to 79 equals the number of students in fifth period who scored from 68 to 79

The scatter plot shows the relationship between the number of chapters and the total number of pages for several books. Use the trend line to predict how many pages would be in a book with 35 chapters.

• 5 pages

• 70 pages

• 220 pages

• 350 pages

Displayed below is a scatter plot with a line of fit along with the corresponding residual plot. What conclusion can be made about the line of fit based on these displays.

• The line of fit has a weak fit with the data because the residual plot shows no pattern.

• The line of fit has a strong fit with the data because the residual plot shows no pattern.

• The line of fit has a weak fit with the data because the residual plot shows a curved pattern.

• The line of fit has a strong fit with the data because the residual plot shows a curved pattern.

What is the relative frequency for selecting a teen given that the person likes chocolate?

• .056

• .112

• .164

• .267

Below is a Samantha’s grades for the first semester and the corresponding weights. Calculate the weighted average.

• 20%

• 83%

• 84.5%

• 103%