A special line graph, called a frequency polygon,can be constructed from the
carry-on luggage histogram by joining the center points at the top of each bar. (See the
graphs below.) On the horizontal axis, we write the coordinate of the middle value of
each bar. After erasing the bars, we get the frequency polygon shown on the right below.Frequency polygon100
5.5 9.5 13.5 17.5
Weight (lb)21.5300500700Frequency9001,100Weight of Carry-on LuggageHistogram100
5.5 9.5 13.5 17.5
Weight (lb)21.5300500700Frequency9001,100Weight of Carry-on Luggage120430970540200602 Chapter 7 Graphs and Statistics
1.$14.70 2. a.32 mphb.11 mphc.a chicken and an elephant 3. a.about $400
billionb.about $700 billionc.about $170 billion4.33 pizzas were delivered to the
co-ed residence hall.5.5.5 million ounces6. a.about 20,000b.about 90,000
7.Train 1, which had been stopped, is beginning to move.8. 200ANSWERS TO SELF CHECKSFor problems 1-6, refer to graphs a through f below. Fill in the
blanks with the correct letter.- Graph is a bar graph.
- Graph is a circle graph.
VOCABULARY
- Graph is a pictograph.
- Graph is a line graph.
- Graph is a histogram.
- Graph is a frequency polygon.
SECTION 7.1 STUDY SET
0.5el= $100Children
Parents
SeniorsIce Cream Sales
at Barney’s Café(f)(c)Flight Arrival Delays
of 15 minutes or more
(in thousands)(^0) '00
200
400
600
800
'01 '02 '03 '04 '05
100
300
500
700
'06 '07 '08
50
10.5 20.5 30.5 40.5
Age
50.5 60.5 70.5
100
150
200
Frequency
250
300
Age of Viewers of a Cable TV Channel
s)
Coal: 23
Renewable: 7
Nuclear: 8
Crude oil: 11
Natural gas: 22
2007 U.S. Energy Production Sources
(in quadrillion BTUs)
(b)
(e)^0 '00
200
400
600
800
100
300
500
700
2003
1.0
0.5
1.5
2.0
2.5
3.0
3.5
4.0
2004 2005 2006
Number of Coupons Redeemed (in billions)
2007 2008
4.5
10
20
30
40
50
60
Frequency
9.5 14.5 19.5
Number of miles driven
Commuting Miles per Week
24.5 29.5
9
13
27
51
(^36) N
(a)
(d)