Understanding Basic Statistics 6th Edition by Charles Henry Brase,Corrinne Pellillo Brase

Exercise 48

Expand Your Knowledge: Sample Size and Significance of Correlation In this problem, we use Table 4-6 to explore the significance of r based on different sample sizes. See Problem 21.
(a) Is a sample correlation coefficient r = 0.820 significant at the = 0.01 level based on a sample size of n = 7 data pairs What about n = 9 data pairs
(b) Is a sample correlation coefficient r = 0.40 significant at the = 0.05 level based on a sample size of n = 20 data pairs What about n = 27 data pairs
(c) Is it true that in order to be significant, 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 significance of r Explain.