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76 UNIT 1 Exploring One-Variable Data

Comparing Distributions with Boxplots and 37. Energetic refrigerators Consumer Reports magazine
Summary Statistics rated different types of refrigerators, including those with
35. Overthinking it? Athletes often comment that bottom freezers, those with top freezers, and those with
pg 68 they try not to “overthink it” when competing in their side freezers. One of the variables it measured was annual
sport. Is it possible to “overthink it”? To investigate, energy cost (in dollars). The following boxplots show the
researchers put some golfers to the test. They recruited energy cost distributions for each of these types. 88
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40 experienced golfers and allowed them some time to
practice their putting. After practicing, they randomly Top
assigned the golfers in equal numbers to two groups.
Golfers in one group were asked to write a detailed
description of their putting technique (which could Side
lead to “overthinking it”). Golfers in the other group
were asked to do an unrelated verbal task for the same
amount of time. After completing their tasks, each Bottom
golfer attempted putts from a fixed distance until they 40 60 80 100 120 140 160
made three putts in a row. Here are parallel boxplots Energy cost ($)
displaying the number of putts required for the golfers
in each group to make three putts in a row, along with (a) From the boxplots, what can you say about the percent-

86
summary statistics. Compare the distributions. age of each type of freezer that costs more than $60 per

year to operate?
Described putting (b) Compare the energy cost distributions for the three

types of refrigerators.
38. Weight-loss strategies Which dieting strategy works best?
Unrelated task Researchers used data from the U.K. television show
How to Lose Weight Well to investigate. In each episode,
0 10 20 30 40 50 60 70 six participants are assigned in pairs to adopt three diet-
Number of putts required to make 3 in a row ing strategies: crashers, shape shifters, and life changers.
The crashers follow extreme diets for 1–2 weeks, such as
replacing meals with bone broth or baby food. The shape
Group Name n Mean SD Min Q 1 Med Q 3 Max shifters follow moderately extreme diets for 4–6 weeks,
Described 20 21.2 15.07 3 11.5 17 28 65 like the blood sugar diet that involves consuming at most
putting 800 calories per day. The life changers follow less-extreme
Unrelated 20 10.6 9.832 3 4 5.5 15.5 37 diets for 12–16 weeks, like low-carbohydrate or Mediterra-
task nean diets. Here are boxplots that summarize the percent-
age of body weight lost by 137 pairs of participants in
36. Who is the GOAT? Which NBA player is the Greatest the TV show over a 5-year period: 89
of All Time: LeBron James or Michael Jordan? Here
are parallel boxplots displaying the average points 25
scored per game by each player in the seasons they
played through 2019, along with summary statistics. 87 20
Compare the distributions.
Percentage of body weight lost 10

James 15

Jordan
22 24 26 28 30 32 34 36 5
Average points scored per game 0

Player x s x Min Q 1 Med Q 3 Max IQR
James 27.16 2.33 20.90 26.55 27.15 27.95 31.40 1.40 –5
Jordan 29.45 4.76 20.00 26.90 30.10 32.60 37.10 5.70
Life Shape Crashers
changers shifters

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