Question

Multiple Choice

1. Given a regression equation of Weight (lbs) = 3.45*Height (inches) – 98.96, how much do expect someone to weigh if they are 67 inches tall?

a) 126.59

b) 132.19

c) 231.15

d) 330.11

2. Given a regression equation of Weight (lbs) = 3.45*Height (inches) – 98.96, what is the residual if a person who is 67 inches tall weighs 140.5 pounds?

a) -90.65

b) -8.31

c) 8.31

d) 90.65

3.  Given a correlation coefficient (r) of 0.8612, mean of x = 114.5, standard deviation of x (s_x) = 26.12, mean of y = 52.3, and standard deviation of y (s_y) = 12.8. Find the slope of the regression line.

a) 0.8612

b) 1.7574

c) 0.4220

d) 2.0406

Answer 1

Q.1) Given that, the regression equation is,

Weight = 3.45 * Height - 98.96

We want to predict Weight for Height = 67 inches

Weight = (3.45 * 67) - 98.96

=> Weight = 231.15 - 98.96

=> Weight = 132.19 lbs

Answer : b) 132.19

Q.2) Actual weight for height = 67 inches is 140.5 and predicted weight (from Q.1)) is 132.19

Residual = Actual value - Predicted value = 140.5 - 132.19 = 8.31

=> Residual = 8.31

Answer : c) 8.31

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Q.3) From given information, we want to find the slope (b1),

b1 = r * Sy / Sx = 0.8612 * 12.8/26.12 = 0.4220

=> b1 = 0.4220

Answer : c) 0.4220