Lesson 4

Dot Plots

Let's investigate what dot plots and bar graphs can tell us.

Problem 1

Clare recorded the amounts of time spent doing homework, in hours per week, by students in sixth, eighth, and tenth grades. She made a dot plot of the data for each grade and provided the following summary.

  • Students in sixth grade tend to spend less time on homework than students in eighth and tenth grades.

  • The homework times for the tenth-grade students are more alike than the homework times for the eighth-grade students.

Use Clare's summary to match each dot plot to the correct grade (sixth, eighth, or tenth).

Three dot plots, time in hours, 10 to 22 by ones.

Problem 2

Mai played 10 basketball games. She recorded the number of points she scored and made a dot plot. Mai said that she scored between 8 and 14 points in most of the 10 games, but one game was exceptional. During that game she scored more than double her typical score of 9 points. Use the number line to make a dot plot that fits the description Mai gave.

A blank dot plot for "points" with the numbers 8 through 22, in increments of 2, indicated.

Problem 3

A movie theater is showing three different movies. The dot plots represent the ages of the people who were at the Saturday afternoon showing of each of these movies.

Three dot plots from 0 to 55 by 1’s. Age. Plots labeled moive A, movie B, and movie C.
  1. One of these movies was an animated movie rated G for general audiences. Do you think it was movie A, B, or C? Explain your reasoning.
  2. Which movie has a dot plot with ages that that center at about 30 years?
  3. What is a typical age for the people who were at Movie A?

Problem 4

Find the value of each expression.

  1. \(3.727 + 1.384\)
  2. \(3.727 - 1.384\)
  3. \(5.01 \boldcdot 4.8\)
  4. \(5.01 \div 4.8\)
(From Unit 5, Lesson 13.)