Given the following data (X=number of push-ups; Y=number of sit-ups):

X	Y
8	18
10	25
14	38
9	21
10	26
9	20
11	28
12	32
9	20
10	23
13	28
9	19

What is the correlation between the number of sit-ups and the number of push-ups?

Test a null hypothesis of rho=0 at the 0.05 level of significance on a one-tailed test.

What percentage of the variation in sit-ups can be explained by variation in push-ups?

Construct a 95% confidence interval for rho.