75. +For a one-tailed test (lower tail) at 93.7% confidence, Z = a. -1.86 b. -1.53 C. -1.96 d. 1-1.645 76. For a two-tailed test, a sample of 20 at 80% confidence, t= a. 1.328 b. 2.539 C. 1.325 d. 2.528 77. For a one-tailed test (upper tail), a sample size of 18 at 95% confidence, t = a. 2.12 b. -2.12 C. -1.740 d. 1.740