SHOW ALL YOUR WORK
1. Consider the following 10 data points:
x 3 5 6 4 3 7 6 5 4 7
y 4 3 2 1 2 3 3 5 4 2
(a) Plot the above observations on a scatterplot.
(b) Calculate the correlation coefficient, r (by hand). What does this value tell
us?
(c) Calculate the least squares regression line.
2. A foods-and-nutrition investigator would like to know if the amount of
sodium (g) can be predicted by the amount of sugar (g) in the following
sample of 12 popular breakfast cereals.
Cereal Sugar (g) Sodium (g)
Mini Wheats 7 0
All-Bran 5 0.26
Apple Jacks 14 0.13
Captain Crunch 12 0.22
Cheerios 1 0.29
Cinnamon Toast Crunch 13 0.21
Corn Flakes 2 0.29
Raisin Bran 12 0.21
Oat Bran 10 0.14
Crispix 3 0.22
Frosted Flakes 11 0.20
Fruit Loops 13 0.13
(a) Identify the response and explanatory variables.
(b) Use JMP output given below and Interpret the slope of the least
squares regression line in the context of this question.
