Question four

A researcher is proposing that exercise makes a person more energized and this results in them

requiring less sleep. He carried out a survey on the number of hours of exercise per week and the

average hours of sleep needed per night in order to feel well rested. The results for the eight (8)

participants are shown below.

Average hours of sleep

needed/night

Hours of exercise/week

4

5.2 2 3.4 8

8.6 8.1

9 8.5

a. Sketch a scatter plot using the data above. Is the relationship linear?

b. What is the correlation between the two variables?

c. Calculate the coefficient of determination and interpret your answer

7.4

10

6.8

1.5 6

9.4

7.7