A national agency sets recommended daily dietary allowances for many supplements. In particular, the allowance for zinc for males over the age of 50 years is 15mg/day. The agency would like to determine if the dietary intake of zinc for active males is significantly higher than 15 mg/day. How many males would need to be included in the study if the agency wants to construct an a =.05 test with the probability of committing a Type II error to be at most .10 whenever the average zinc content is 15.3 mg/day or higher? Suppose from previous studies they estimate the standard deviation to be approximately 4 mg/day.