solution

The data in the fi le Sleep Height was obtained from a
survey of statistics students. The variables recorded are the student’s heights
(in inches) and the amount of sleep they typically get on a school night (in
hours). Consider conducting an analysis to test whether the sample data provide
strong evidence of a negative association between sleep and height.

 a. Describe the population slope in the context of the
study and assign a symbol to it.

b. State the appropriate null and alternative hypotheses in
terms of the population slope using the symbol used in part (a).

 c. Use a theory-based approach to find a p-value. Do you
have strong evidence of a negative association between sleep and height?

d. There are a couple of errors in the data set. It appears
as though two students reported their heights as 55 inches and they sleep 10
hours a night. Since all of the answers on the survey were identical for these
two entries, it would appear they came from the same person. It is also obvious
to the instructor that there was nobody in class as short as 55 inches, so we
know the height is an error. Eliminate these two points (they are the last ones
on the list) and find a new p-value. Do you now have strong evidence of a
negative association?