A health researcher conducts a survey of the relation of proportion of fat in a person's diet to proportion of time the person uses a seat belt

Question

(The idea is that those who practice one kind of health-related behavior may be more likely to practice another kind.) Here are the scores for three participants.
M = 36.67 SD = 10.27 M = 53.33 SD = 12.47 r = ?.96
a. Give the Z score prediction formula for predicting seat belt usage from fat in their diet.
b. Predict the seat belt usage of a person who has 40% fat in their diet.
c. Explain what you have done to a person who is familiar with correlation but not with regression.
What will be an ideal response?

Answer 1

a. Predicted ZY = (−.96)(ZX).
b. ZX = (40 −?36.67)/10.27 = .32; predicted ZY (−.96)(.32) = −.31
Predicted Y = 53.33 + (−.31)(12.47) = 49.46% seat belt usage.
c. Answers will vary
102) A researcher studying the relation of similarity to attraction reported the following results:
M = 3.25 SD = 1.92 M = 6 SD = 2.55 r = .36
a. Give the Z score prediction formula for predicting attraction from similarity.
b. Predict the attraction to a person for whom the similarity is rated as a 5.
c. Explain what you have done to a person who is familiar with correlation but not with regression.
Answer: a. Predicted ZY = (.36)(ZX).
b. ZX = (5−3.25)/1.92 = .91; predicted ZY (.36)(.91) = .33
Predicted Y = 6 + (.33)(2.55) = 6.84.
c. Answers will vary
Person % Fat in Diet % Seat Belt Usage
Tested X ZX Y ZY
K 25 −1.14 70 1.34
L 35 −.16 50 −.27
M 50 1.30 40 −1.07
Person Similarity Attraction
Tested X ZX Y ZY
J.L. 1 −1.17 3 −1.18
K.M. 6 1.43 5 −.39
L.B. 2 −.65 6 0
R.C. 4 .39 10 1.57