1. A research report includes the statement, " = 2.18, < 05." What happened in the hypothesis test? a. The obtained sample mean was very unlikely if the null hypothesis is true, so Ho was rejected. b. The obtained sample mean was very likely if the null hypothesis is true, so H. was rejected. c. The obtained sample mean was very unlikely if the null hypothesis is true, and the test failed to reject Ho. d. The obtained sample mean was very likely if the null hypothesis is true, and the test failed to reject Ho. 3. What assumption is needed before you can use the unit normal table to find critical values for a z-score hypothesis test? a. The population of scores before treatment is normal. b. The scores are obtained by random sampling. c. The scores in the sample are independent observations. d. The distribution of sample means is normal