Warm Up

1) How many Lostcreek memberships were sold during the four day period?

2) Which country club experienced the best sales?

HistogramsSection 13-5

Objectives

Previously, you have already displayed data in a stem-and-leaf plot. (Lesson 13–2)

• Today, we will display data in a histogram.

• Also, we will interpret data in a histogram.

Vocabulary

• histogram A histogram uses bars to display numerical data that have been organized into equal intervals

Parts of a Histogram

Salary at the Acme Corporation

Title

y-axis

x-axis

units

units

Interpreting a Histogram

Read the ……… Title

Units

Number Values

Intervals

Example 1A. ELEVATIONS Use the histogram. How many states have highest points with elevations at least 3751 meters?

Since 11 states have elevations in the 3751–5000 range and 1 state has an elevation in the 5001–6250 range, 11 + 1 or 12 states have highest points with elevations at least 3751 meters.Answer: 12 states

Example 1B. ELEVATIONS Use the histogram. What percent of states contain elevations above 2500 meters?

There are 22 + 13 + 3 + 11 + 1 or 50 states.There are 3 + 11 + 1 or 15 states that have elevations above 2500 meters.

Answer: So, the percent of states with

elevations above 2500 meters is or

30%.

Example 2

A. 28 states

B. 30 states

C. 35 states

D. 40 states

C. ELEVATIONS Use the histogram. How many states have highest points with elevations less than 2501 meters?

Example 2

A. 50%

B. 56%

C. 60%

D. 65%

D. ELEVATIONS Use the histogram. What percent of states contain elevations above 1250 meters?

Example 3EMPLOYMENT Use the histograms. Which business sector has more states with the number of employees in the interval 1001 to 3000?

Answer: So, the service sector has more.

The trade sector has 5 + 1 or 6 states and service sector has 8 + 3 or 11 states in the interval 1001 to 3000.

Example 4

A. East Coast

B. West Coast

C. Both have an equal number of people spending at least $60 weekly.

D. cannot be determined

EATING OUT Use the histograms. Which coast has more people spending at least $60 weekly?

Great, we can read a histogram, but how do we create a histogram?

Histograms are bar graphs where the bars touch.

Histograms also measure frequency. Therefore, we need to create a

frequency table of the data. We must also figure out what size to

make the intervals. We should have at least 5 – 7 intervals.

Example-Test Scores on an 11th Grade Science Test

The test scores on an 11th grade science test: 58, 91, 78, 84, 93, 65, 73, 69, 77, 83, 80, 90, 85, 74, 61, 71, 83, 76, 63, 70

Step 1: Find the range 93-58=35 Step 2: Determine the size of the

intervals 35÷7=5 (the intervals will 5 scores) Step 3: Create a frequency table Step 4: On the x-axis, space out your

intervals; on the y-axis, put the frequency

Step 5: Label the axes Step 6: Draw the graph

Scores

Frequency

58-62 2

63-67 2

68-72 3

73-77 4

78-82 2

83-87 4

88-93 3

Here’s the Histogram

58-62 63-67 68-72 73-77 78-82 83-87 88-93

4

3

2

1

0

Science Test Scores

Frequency

Scores