Lesson 4: Practice Problems

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.

  1. sixth grade

  2. eighth grade

  3. tenth grade

  1. A dot plot with a range of 10 to 22. Data as follows: 10-13, and 22, no data. 14 (1), 15(1), 16(2), 17(3), 18(3) 19(4), 20(3), 21(3).
  2. A dot plot with a range of 10 to 22. No data at 10, 12, 21, and 22. Data as follows: 11(1), 13(3), 24(2), 15(2), 16(4), 17(3), 18(3), 19(1), 20(1).
  3. A dot plot with a range of 10 to 22. No data at 10-15, 21-22. Data as follows: 16(2), 17(6), 18(9), 19(2), 20(1).

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 dotplots for age are labeled "movie A", "movie B", and "movie C" each with the numbers 0 through 55, increments of 5, indicated. Movie A has the following data: age 31, 1 dot; age 32, 1 dot; age 35, 1 dot; age 37, 2 dots; age 38, 3 dots; age 39, 4 dots; age 40, 3 dots; age 41, 1 dot; age 42, 2 dots; age 43, 4 dots; age 44, 2 dots; age 45, 1 dot; age 46, 2 dots; age 48, 1 dot; age 53, 1 dot; age 54, 1 dot. Movie B has the following data: age 3, 1 dot; age 4, 8 dots; age 5, 4 dots; age 6, 4 dots; age 7, 3 dots; age 8, 5 dots; age 9, 4 dots; age 10, 1 dot; age 26, 1 dot; age 27, 1 dot; age 28, 3 dots; age 30, 3 dots; age 31, 3 dots; age 32, 1 dot; age 38, 1 dot; age 40, 1 dot; age 41, 1 dot; age 43, 1 dot; age 45, 1 dot; age 46, 1 dot; age 49, 1 dot; age 50, 1 dot. Movie C has the following data: age 21, 2 dots age 22, 2 dots; age 25, 2 dots; age 26, 2 dots; age 27, 2 dots; age 28, 3 dots; age 30, 1 dot; age 31, 1 dot; age 32, 1 dot; age 33, 4 dots; age 35, 3 dots; age 36, 2 dots; age 37, 1 dot; age 38, 3 dots; age 39, 1 dot.

  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 From Unit 5 Lesson 13

Find the value of each expression.