What is the critical value for a one-tailed ztest? For a two-tailedz test? Which is more likely to result in a rejection of the null hypothesis? Why?

Why doest_cv.Change when the sample size changes? What must be computed to determine t_cv.?

Given a population standard deviation of 12, answer the following two questions.
4) Calculate the standard deviation of the mean (given the following two sample sizes (show all your work and round to two decimal places): N1 = 20 N2 = 70
5) How does the sample size change the standard error of the mean? What does this mean for statistical power?

Calculate the critical degrees of freedom and identify the critical values for the following tests, using p = .05 and the tables in your e-book for all scenarios (do NOT round). Then, state whether the null hypothesis would be rejected or failed to be rejected.
6) Single sample t-test: two-tailed, N = 20, t= 2.05	df= ANSWER	critical t = ANSWER	Reject or Fail to Reject Ho: ANSWER
7) Single sample t-test: one-tailed, N = 20, t= 2.05	df= ANSWER	critical t = ANSWER	Reject or Fail to Reject Ho: ANSWER
8) Pearson's rcorrelation: two-tailed, N = 15, r= 0.47	df= ANSWER	critical t = ANSWER	Reject or Fail to Reject Ho: ANSWER
9) Pearson's rcorrelation: one-tailed, N = 15, r= 0.47	df= ANSWER	critical t = ANSWER	Reject or Fail to Reject Ho: ANSWER