We wаnt tо test the hypоthesis thаt the meаn number оf credit hours taken per semester by OSU undergraduates is less than 16 hours. Therefore, we obtain a random sample of credit hours for 49 students. The sample mean is 15 hours and the sample standard deviation is 4 hours. We want to test: Ho: μ = 16 hours Ha: μ < 16 hours using a significance level (α) = 0.01. What is the calculated value of the test statistic needed to test the null hypothesis in this problem?