Skip to lesson

Choose “Save as PDF” in the print dialog to keep a copy.

Cogito

Probability and Statistics · Chapter 1 · Lesson 3

Practice Worksheet

Box Plots and the Five-Number Summary

Five numbers describing a whole data set.

12 problems · about 21 minutes · TEKS P.S.1.C, S-ID.A.1

NameDate

Figure — use these to answer the problems

Change the values and watch the quartiles move. Each section always holds a quarter of the points.
020
  • Minimum3
  • Lower quartile5
  • Median8
  • Upper quartile13
  • Maximum19
  • Interquartile range8
Value 13
Value 25
Value 37
Value 48
Value 59
Value 613
Value 719
Figure 1

Warm Up

Straightforward practice. Get the method working first.

5 problems

  1. Q1 = 12, Q3 = 20. What is the IQR?

    Answer

  2. What does a wide section of a box plot mean?

    • Those values are spread thin, though the count is the same.
    • More data points lie in that section.

  3. Q1 = 10, Q3 = 22. What is the IQR?

    Answer

  4. Data 3, 5, 7, 8, 9, 13, 19. What is the median?

    Answer

  5. Same data. What is Q1?

    Answer

Build It Up

The same ideas with more to keep track of.

3 problems

  1. Same data. What is Q3?

    Answer

  2. Q1 = 4, IQR = 6. What is the lower outlier fence?

    Answer

  3. What fraction of the data lies in the box, as a decimal?

    Answer

Stretch Yourself

Mixed problems. Work out what kind of question it is before you start.

4 problems

  1. Match each part of the summary with what it reports.

    Draw a line from each item on the left to its match on the right.

    • Median
    • IQR
    • Range
    • The centre value
    • The spread of the middle half
    • Maximum minus minimum

  2. A box section is very wide. Does it hold more points or the same? 1 more, 2 the same.

    Answer

  3. The Spread

    Lower quartile 5, upper quartile 13. What is the IQR?

    Answer

  4. The Fence

    IQR 8 and upper quartile 13. What is the upper outlier fence?

    Answer