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Unformatted text preview: Correlation 1. I believe that people who prefer chocolate will avoid other candles and vice
versa. In order to test this hypothesis, I give six of my family members
identical Easter baskets. I observe how many jelly beans and how many
Cadbury Creme Eggs (chocolate!) each person eats. Below are the results. Calculate the correlation coefﬁcient. 1332. (3 q
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number of jelly beans eaten and whether or not that person had fully consumed the ‘ q L"
chocolate Easter bunny in their basket. What type of correlation would this be? varrwlau. cudOM Mekowmwl fuseLu. Assume that I gather jelly bean and Easter bunny data from 20 people and ﬁnd r =
.50. I code the Easter bunny data using 0 = “bunny not eaten” and 1 = “bunny
eaten”. What does this tell us about the relationship between jelly bean and Easter
bunny consumption? “were. 3w»? SpaceM Mu. ecu*1 who: Queer
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new? 44443 wrt— M “ K gang“; Whﬁ‘ﬁ’ ‘ Draw a scatterplot of the second result (bunny eaten vs. jelly beans eaten). Be sure
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If I switched the coding for the bunny data, how would this change the coefﬁcient?
W Co 24.80 w’r would be. com MW“ 2. In order to examine the relationship between kids’ ages and the amount of
time they spend playing video games, a researcher collects data from 100
firstgraders and 100 high school seniors. She ﬁnds that the relationship is
very strong (r = .84). Describe the ﬂaw in her methodology and how it may
have impacted her r—vaiue. 1.1.“ ate.“ :1 (1 Cu M4!" 1? Way»
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restricted ran e problem. How would this affect r? I n N Wv‘ﬁ a M§IL  a . j
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4. Give an example of a Spearman rankorder correlation in which r would be negative. Be sure to describe your variables. Under what circumstances
would a Spearman correlation be referable to a Pearson correlation? 14 qauvanvc, 'mdwy S' be? Wynne—r; ClHMP‘éf‘ﬂﬁ?
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 Fall '09

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