Expand Your Knowledge: Sample Size and Signifi cance of Correlation In this problem, we use Table 4-6 to explore the signifi cance of r based on different sample sizes. See Problem 21.

(a) Is a sample correlation coeffi cient r 5 0.820 signifi cant at the a 5 0.01 level based on a sample size of n 5 7 data pairs? What about n 5 9 data pairs?

(b) Is a sample correlation coeffi cient r 5 0.40 signifi cant at the a 5 0.05 level based on a sample size of n 5 20 data pairs? What about n 5 27 data pairs?

(c) Is it true that in order to be signifi cant, an r value must be larger than 0.90? larger than 0.70? larger than 0.50? What does sample size have to do with the signifi cance of r? Explain.