7th Grade Math

R30 Selected Answers and Solutions

Selected Answers and Solutions

13. stem-and-leaf plot; displays individual data
    Number of Push-Ups
    Stem Leaf
    1
    2
    3
    4
    5

0 7 9

0 3 3 5 8 8 8 8

1 2 3 4 4 5 6 6 7

(^1) | 0 means 10 push-ups
15.
English Social Studies
822
13
17
Subjects Studied
17a.
0
10
20
30
40
50
60
Percent of Total Volume
Superior
Erie
Michigan
HuronOntario
Great Lakes
Volume of the Great Lakes
17b. Sample answer: The circle graph is most
appropriate because it shows how each lake
compares to the whole. 19. Sample answer: The
population of polar bears over the last 10 years.

21. Sample answer: A box-and-whisker plot clearly
    shows the least and greatest values. Then the range
    can be found by subtracting the least value from
    the greatest. 23. Sample answer: Numerical data
    that can be displayed using consecutive intervals
    are best displayed in a histogram. 25. Graph A;
    Sample answer: The scale used makes the increase
    appear less signifi cant.

Pages 546–549 Chapter Study Guide and Review

1. true 3. false; measures of variation 5. true


2. true 9. false; outlier 11. 80; 86; no mode


3. 11; 5; 6, 4; 2; 14 is an outlier 15. The mean is
   22.4; the median is 21; there is no mode. The range
   is 35. The appropriate measure of central tendency
   is the median. The mean is not appropriate because
   it is affected by the extremely high number, 42, and
   low number, 7. 17. Sample answer: The data
   between the median and the upper and lower
   quartile are more spread out than compared to any
   other part of the box-and-whisker plot because the

length of this section is longer than any other

section. The data in the other sections are equally

spread out because of their lengths.

012 345

19. 5 seconds 21. Most runners were in the 60–64
    interval.


20. 
    

6

8

4

0

2

Number of Plants

Height (inches)

1–56–1011–1516–2021–25

Plant Heights

25. Points Scored
    Stem Leaf
    5
    6
    7
    8
    9

3

5 8 8

3 5 7 7 9

1 2 (^7) | 5 = 75 points

27. 1.7 points per game 29. Sample answer: stem-
    and-leaf plot

Chapter 10 Volume and

Surface Area

Page 556 Chapter 10 Are You Ready?

1. 25 yd^2 3. 875 ft^2 5. 379.9 in^2 7. 78.5 cm^2
   Pages 561–563 Lesson 10-1B


2. 220 in^3 3. 63 yd^3 5. second cabinet;
   37.5 ft^3 < 63 ft^3 7. 90 ft^3 9. 236.3 cm^3
   1111 V = Bh^ Volume of a prism

V = (^) ( 1 2 · 6 · (^4) ) h Replace B with ^12 · 6 · 4.
V = (^) ( 1 _ 2 · 6 · (^4) ) 9 The height of the prism is 9.
V = 108 Multiply.
The volume is 108 cubic meters or 108 m^3.

13. 20.4 mm^3 15. 40 ft^3 > 36 ft^3 , so too much was
    bought. 17. 166 _^14 yd^3 19a. 2,157,165 ft^3
    19b. 98,053 ft^3
    2121 First, fi nd the volume of the offi ce.
    V = wh Volume of a prism
    V = 32 · 25 · 12  = 32, w = 25, h = 12
    V = 9,600 Multiply.
    The volume of the office is 9,600 cubic feet.
    Next, find the cost to air condition the office
    for a year. Find the product of the cost per cubic
    foot and the number of cubic feet. The cost to

R01_R42_EM_SelAns_895130.indd R30 1/18/10 9:51 AM