Lesson 5

Using Dot Plots to Answer Statistical Questions

Let's use dot plots to describe distributions and answer questions.

Problem 1

Three sets of data about ten sixth-grade students were used to make three dot plots. The person who made these dot plots forgot to label them. Match each dot plot with the appropriate label.

Three dot plots labeled A, B, C.
A:

Dot Plot A

B:

Dot Plot B

C:

Dot Plot C

1:

Ages in years

2:

Numbers of hours of sleep on nights before school days

3:

Numbers of hours of sleep on nights before non-school days

Problem 2

The dot plots show the time it takes to get to school for ten sixth-grade students from the United States, Canada, Australia, New Zealand, and South Africa.

Five dot plots. 
  1. List the countries in order of typical travel times, from shortest to longest.
  2. List the countries in order of variability in travel times, from the least variability to the greatest.

Problem 3

Twenty-five students were asked to rate—on a scale of 0 to 10—how important it is to reduce pollution. A rating of 0 means “not at all important” and a rating of 10 means “very important.” Here is a dot plot of their responses.

A dot plot, importance of reducing pollution, 2 to 10 by ones. Beginning with 2, the number of dots above each increment is 1, 1, 1, 2, 2, 2, 5, 5, 6.

Explain why a rating of 6 is not a good description of the center of this data set.

Problem 4

Tyler wants to buy some cherries at the farmer’s market. He has $10 and cherries cost $4 per pound. 

  1. If \(c\) is the number of pounds of cherries that Tyler can buy, write one or more inequalities or equations describing \(c\).
  2. Can 2 be a value of \(c\)? Can 3 be a value of \(c\)? What about -1? Explain your reasoning.
  3. If \(m\) is the amount of money, in dollars, Tyler can spend, write one or more inequalities or equations describing \(m\).
  4. Can 8 be a value of \(m\)? Can 2 be a value of \(m\)? What about 10.5? Explain your reasoning.
(From Unit 7, Lesson 10.)