1. A population is known to have a mean of u = 50. A treatment is expected to increase scores for individuals in this population. If the treatment is evaluated using a one-tailed hypothesis, then which of the following is the correct statement of the null hypothesis? a. u > or equal to 50 b. u. > 50 c. u < or equal to 50 d. u < 50 3. A researcher expects a treatment to produce an increase in the population mean. Assuming a normal distribution, what is the critical z-score for a one. tailed test with a = 01? a. +2.33 b. 2.58 c. +1.65 d. #2.33