Page 55 - 2024-bfw-starnes-TPS7e-SE proofs.indd

42 UNIT 1 Exploring One-Variable Data

21. Arizona heat Here is a stemplot of the high tempera- 24. Finch evolution Biologists Peter and Rosemary Grant
ture readings (in degrees Fahrenheit) for Phoenix, spent many years collecting data on finches in a remote
Arizona, for each day in July in a recent year: 47 part of the Galápagos Islands. Their research team
caught and measured all of the birds in more than
8 4 20 generations of finches. The back-to-back stemplot
8 shows the beak depths (in millimeters) of 89 finches
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9 3
9 799 captured the year before a drought occurred and 89
10 011223444 finches captured the year after the drought occurred. 49
10 556667788999 Compare the distributions of beak depth in these two
11 0113 years.
11 5

(a) Why did we split the stems? Before drought After drought
(b) Give an appropriate key for this stemplot. 2 6

(c) Describe the shape of the distribution. Are there any 8 6 KEY: 10 | 0 = 10.0 mm
beak depth
outliers? 411 7 7 1 9
98
22. Watch that caffeine! The U.S. Food and Drug Admin- 44420 8 044
9999977765555
istration (FDA) limits the amount of caffeine in a 444321111100000 8 9 778
0011123344
12-ounce can of carbonated beverage to 72 milligrams. 99999888887777655 9 5666666777789999
That translates to a maximum of 48 milligrams of caf- 444433322111111000 10 000222223333334444
feine per 8-ounce serving. Data on the caffeine content 8766655555 10 55555566666777778999
11
0000111134444
440
of popular soft drinks (in milligrams per 8-ounce serv- 7 11 5667
ing) are displayed in the stemplot.
1 556 Displaying Quantitative Data: Histograms
2 033344
2 55667778888899 25. Carbon dioxide emissions Burning fuels in power
3 113 pg 33 plants and motor vehicles emits carbon dioxide ( CO ),

2
3 55567778 which contributes to global warming. The table dis-
4 33 plays CO emissions in metric tons per person from 48

4 77 2
countries with populations of at least 20 million in a

(a) Why did we split the stems? recent year. 50
(b) Give an appropriate key for this graph.

(c) Describe the shape of the distribution. Are there any Country CO 2 Country CO 2 Country CO 2

outliers? Algeria 4.0 Italy 5.6 South Africa 8.2
23. Acorns and oak trees Of the many species of oak trees in Argentina 4.0 Japan 8.7 Spain 5.4
the United States, 28 grow on the Atlantic Coast and 11 Australia 16.3 Kenya 0.3 Sudan 0.5
grow in California. The back-to-back stemplot displays Bangladesh 0.6 Korea, North 1.5 Tanzania 0.2
data on the average volume of acorns (in cubic centime- Brazil 2.2 Korea, South 11.9 Thailand 4.1
ters) for these 39 oak species. Compare the distributions of Canada 15.4 Malaysia 7.8 Turkey 4.9
acorn size for the oak trees in these two regions. 48
China 7.1 Mexico 3.4 Ukraine 5.1
Atlantic Coast California Colombia 2.0 Morocco 2.0 United Kingdom 5.5
998643 0 4 Congo 0.6 Myanmar 0.5 United States 16.1
88864211111 1 06
50 2 06 Egypt 2.5 Nepal 0.5 Uzbekistan 3.3
6640 3 Ethiopia 0.2 Nigeria 0.7 Venezuela 4.1
8 4 1 France 5.0 Pakistan 1.2 Vietnam 2.6
5 59
8 6 0 Germany 8.4 Peru 1.7
7 1 Ghana 0.5 Philippines 1.3
1 8 India 1.9 Poland 8.5
1 9
5 10 Key: 2|6 5 An oak species Indonesia 2.3 Romania 3.9
11 whose acorn volume Iran 9.4 Russia 11.5
12 is 2.6 cm . 3
13 Iraq 5.6 Saudi Arabia 17.0
14
15
16
17 1

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