Calculate the correlation coefficient for the number of years out of school and annual contribution data in Try It Yourself 1. Interpret the result in the context of the data.

a. Identify n and use a table to calculate ­∑x, ∑­y, ∑­xy, ­∑x², and ∑­y².

b. Use the resulting sums and n to calculate r.

c. Interpret the result in the context of the data.

Number of years out of school, x                 Annual contribution (in 1000s of $), y

1 …………………………………………………………………………..   12.5

10 …………………………………………………………………………..  8.7

5 …………………………………………………………………………..   14.6

15 …………………………………………………………………………..  5.2

3 …………………………………………………………………………..    9.9

24 …………………………………………………………………………..  3.1

30 …………………………………………………………………………..  2.7