7th Grade Math

Test PracticeT

524 Statistical Displays

12. GRIDDED RESPONSE The graph
    shows the amount of sugar per serving
    in various adult cereals.

Sugar per Serving

in Adult Cereals

Number of Cereals

Number of Grams

(^0) 0–2 3–5 6–8 9–11
2
4
6
8
10
12
14
How many kinds of cereal contain
6–8 grams of sugar per serving?

13. SHORT RESPONSE A group of
    mothers reported when their children
    got their first tooth.

2

4

6

8

10

0

0–1 2–3 4–5 6–7 8–9

Child’s Age at First Tooth

Number of Children

Age (months)

What fraction of the number of children

reported got their first tooth when they

were six months old or older?

Histograms

More

AboutAbout

Relative frequency is the ratio that compares the frequency of each category

to the total. Cumulative relative frequency of two or more categories is the

ratio of the combined frequencies to the total.

SLEEP The table shows the results of a class

survey about the number of hours of sleep

students get each night. What fraction of

students get less than 8 hours of sleep

each night?

Find the cumulative relative frequency.

There were 20 students surveyed. And

2 + 2 + 7 or 11 students get less than 8 hours of sleep each night.

So, _^1120 of students surveyed get less than 8 hours of sleep each night.

WALKING The table shows the number of minutes

Penny walked her dog each day this month.

14. What fraction of the days did she walk her dog
    12 minutes or less? Write in simplest form.


15. What fraction of the days did she walk her dog
    less than 16 minutes? Write in simplest form.

Number of Minutes Number of Days

10 10

12 6

14 4

16 2

18 8

Number of Hours Number of Students

52

62

77

88

91

513_531_C09_L3_895130.indd 524 1/11/10 9:40 AM