For each of the following circumstances, perform the indicated hypothesis tests:
a. HA: r > 0, r = 0.53, and n = 30 with α = 0.01, using a test-statistic approach.
b. HA: r ≠ 0, r = - 0.48, and n = 20 with α = 0.05, using a p -value approach.
c. HA: r ≠ 0, r = 0.39, and n = 45 with α = 0.02, using a test-statistic approach.
d. HA: r < 0, r = 0.34, and n = 25 with α = 0.05, using a test-statistic approach.