S
00XP
← Unit 3 · Pie graphs, dot plots, stem-and-leaf

Lesson

Read the rule, then work each example: try the setup yourself, then tap to check one step at a time.

The rules

Pie graph

Percent = f ÷ n × 100; degrees = f ÷ n × 360°. 'A or B' → add the two percents; 'how many of 500' → percent × 500.

Dot plot

One dot per data value: n = count every dot; 'how many have 2' = dots above 2; mode = tallest stack.

Stem-and-leaf plot

Stem = all digits except the last; leaf = the last digit. Highest = last stem + its last leaf; lowest = first stem + first leaf.

Traps and calculator keys are on the unit page →

Worked examples (8)

Example 1 · 1.3 #10/8

A survey asked if people would like to spend the rest of their careers with their present employers. The results are shown. Construct a pie graph for the data.

AnswersNumber of peoplePercent
YES689___
NO361___
UNDECIDED78___
Total______

Try the setup yourself first, then tap.

Example 2 · 1.3 #20/6

The data below show the number of songs on each CD from a collection. Construct a dotplot for the data.

15 10 11 12 15 20 15 10 12 15
13 14 15 14 20 14 11 10 12 15

Try the setup yourself first, then tap.

Example 3 · 1.3 #3a0/4

a) How many CDs are there from the collection?

Use the dot plot in exercise 2 to answer the questions

Try the setup yourself first, then tap.

Example 4 · 1.3 #3b0/4

b) How many CDs can hold 20 songs?

Use the dot plot in exercise 2 to answer the questions

Try the setup yourself first, then tap.

Example 5 · 1.3 #3c0/4

c) How many songs were most recorded on the CDs?

Use the dot plot in exercise 2 to answer the questions

Try the setup yourself first, then tap.

Example 6 · 1.3 #40/11

The number of visitors to the Railroad Museum during 24 randomly selected hours is shown here. Construct a stem and leaf for the data below.

67 62 38 73 34 43 72 35
53 55 58 63 47 42 51 62
32 29 47 62 29 38 36 38

Try the setup yourself first, then tap.

Example 7 · 1.3 #5a0/4

a) What is the least number of visitors to the Railroad Museum during one selected hour?

Use the stem and leaf plot in exercise 4 to answer the questions

Try the setup yourself first, then tap.

Example 8 · 1.3 #5b0/4

b) The number of visitors ranges between which two values?

Use the stem and leaf plot in exercise 4 to answer the questions

Try the setup yourself first, then tap.

Practice nowTake the checkpoint