Question

A researcher collects data on the relationship between the amount of daily exercise an individual gets and the percent body fat of the individual. The following scores are recorded.

Individual 1 2 3 4 5
Exercise (min) 10 18 26 33 44
% Fat 30 25 18 17 14
Individual: 1, 2, 3, 4, 5

Excercise (min): 10, 18, 26, 33, 44
% Fat: 30, 25, 18, 17, 14
a) Based on the above data, if an individual exercises 20 minutes daily, his predicted % body fat would be


a. 21.63
b. 27.74
c. 27.88
d. 23.75

Answer 1

Option D is correct.

If exercise time = 20 mins,

Body fat = 23.75%

Explanation:

After plotting a graph of the variables given, with body fat on the x-axis and exercise time on the y-axis.

The equation of the graph was obtained to be

Y = -1.931X + 65.936

If exercise time = 20 mins,

Y = 20

20 = -1.98X + 66.936

-1.98X = -46.936

X = 23.7 = 23.75% From the options.

The problem can also be solved by doing the least squares regression line method, but this is more straight forward.