Comparing Two Graphs

So far, we have looked at single graphs and made inferences about one population. Now we are going to compare two graphs and make inferences about two populations.

We will see examples of a:• Double Line Plot• Back-to-back Stem and Leaf Plot• Double Bar Graph/Histogram• Double Box Plot

Which statement is true?

A. Danielle’s times are more spread out.

B. Katie’s times are more spread out.

The double line plot shows the number of minutes Katie and Danielle trained for a cross-country run.

Which statement is true?

A. Danielle’s times are more consistent.

B. Katie’s times are more consistent.

Find the mean of each line plot. Who has higher average training time?

Katie’s Average Time: 64.9 minDanielle’s Average Time: 70.8 min

Danielle has the higher average training time.

The double histogram shows the heights of the tallest buildings in Atlanta and Charlotte.

Which statement is true?

A. Atlanta has the tallest building.

B. Charlotte has the tallest building.

Which statement is true?

A. Atlanta has more buildings that are 800-899 ft tall.

B. Charlotte has more buildings that are 800-899 ft tall.

The back-to-back stem and leaf plot shows the number of wins of two middle school baseball teams

for the past ten years.

Which statement is true?

A. Westland MS has a more consistent number of wins.

B. Eastfield MS has a more consistent number of wins.

Find the median number of wins for each team.

Westland: 24 games

Eastfield: 26 games

The double box plot shows the height (in inches) of the boys and girls in Ms. Castle’s class.

Which statement is true?

A. The boys are generally taller.

B. The girls are generally taller.

The double box plot shows the height (in inches) of the boys and girls in Ms. Castle’s class.

Which statement is true?

A. 75% of boys are 67 inches or shorter.

B. 75% of girls are 67 inches or shorter.

Find the Inter-quartile Range for girls and boys.

What do you notice? What does this mean?

Girls IQR: 67-64 = 3

Boys IQR: 69-66 = 3

They are the same. This means 50% of the heights are equally spread out around the medians.

Practice:Comparing Two Graphs Worksheet