Question

Most of us love a bowl of cereal every now and then. Some common cereal brands with calories and fat per grams per serving are given in the table below. Is a cereal's calorie content determined by it's fat content?A. Draw the scatterplot for the variables b. Describe the relationship, if any, shown by the scatterplot.c. Calculate r, the correlation coefficient. How does the correlation coefficient compare to the relationship you saw in the scatterplot?

Cereal:                            Calories(per serving):            Fat (per gram):

Almond Delight                    110                                        2                

Apple Jacks                           110                                       2

Bran Chex                             90                                       1

Cap n Crunch                       120                                       2

Cheerios                                110                                        2

Cinnamon Toast Crunch           120                                   3

Corn Flakes                            100                                      0

Honey Nut Cheerios               110                                       1

Honeycomb                             110                                     0

Lucky Charms                          110                                      1

Special K                                 110                                      0

Grape nuts                                110                                     0

Cocoa puffs                              110                                     1

Corn pops                                 110                                     0

Frosted Flakes                         110                                       0

Froot Loops                              110                                      1

Answer 1

Most of us love a bowl of cereal every now and then. Some common cereal brands with calories and fat per grams per serving are given in the table below. Is a cereal's calorie content determined by it's fat content?

A. Draw the scatterplot for the variables

b. Describe the relationship, if any, shown by the scatterplot.

The plot shows that there is a positive relation between calories and fat.

c. Calculate r, the correlation coefficient. How does the correlation coefficient compare to the relationship you saw in the scatterplot?

Excel used for calculation.

Correlation Matrix
		Calories	Fat
	Calories	1.0000	0.4059
	Fat	0.4059	1.0000
		16	sample size
		± .497	critical value .05 (two-tail)
		± .623	critical value .01 (two-tail)

The correlation coefficient r=0.4059. The correlation is positive. This confirms the results of the scatterplot.