Lesson 6: Practice Problems

Problem 1

Here is data that shows student’s scores for 10 rounds of a video game.

  • 130

  • 150

  • 120

  • 170

  • 130

  • 120

  • 160

  • 160

  • 190

  • 140

What is the median score?

  1. 125

  2. 145

  3. 147

  4. 150

Problem 2

When he sorts the class’s scores on the last test, the teacher notices that exactly 12 students scored better than Clare and exactly 12 students scored worse than Clare. Does this mean that Clare’s score on the test is the median? Explain your reasoning.

Problem 3

Match each dot plot with its median.

median

  1. 6

  2. 12

  3. 13

  4. 15

dot plot

  1. A dot plot with one dot at 1, 2, 7, 9. Two dots at 5, 6, 7.
  2. A dot plot with one dot at 17-29, two dots at 10-11, and three dots at 15.
  3. A dot plot with one dot at 5, 6, 9, 13-14. Two dots at 11 and three dots at 15.
  4. A dot plot with one dot at 14, two dots at 8, 10, 11, and three dots at 16.

Problem 4

Ten sixth-grade students reported the hours of sleep they get on nights before a school day. Their responses are recorded in the dot plot.

A dot plot for "hours of sleep". The numbers 5 through 12 are indicated. The data are as follows: 5 hours, 1 dot; 6 hours, 1 dot; 7 hours, 3 dots; 8 hours, 3 dots; 9 hours, 2 dots; 10 hours, 0 dots; 11 hours, 0 dots; 12 hours, 0 dots.

Looking at the dot plot, Lin estimated the mean number of hours of sleep to be 8.5 hours. Noah’s estimate was 7.5 hours. Diego’s estimate was 6.5 hours.

Which estimate do you think is best? Explain how you know.

Problem 5

In his history class, Han’s homework scores are:

  • 100

  • 100

  • 100

  • 100

  • 95

  • 100

  • 90

  • 100

  • 0

The history teacher uses the mean to calculate the grade for homework. Write an argument for Han to explain why median would be a better measure to use for his homework grades.

Problem 6

The dot plots show how much time, in minutes, students in a class took to complete each of five different tasks. Select all the dot plots of tasks for which the mean time is approximately equal to the median time.

  1. dot plot
  2. dot plot
  3. dot plot
  4. dot plot
  5. dot plot

Problem 7

Here is a set of coordinates. Draw and label an appropriate pair of axes and plot the points. , , ,

blank grid