1. Suppose we are testing the null hypothesis H0: µ = 50 and the alternative Ha: µ ≠ 50 for a normal population with σ = 6. The 95% confidence interval for the mean is (51.3, 54.7). Then
A. the P -value for the test is greater than 0.05.
B. the P -value for the test is less than 0.05.
C. the P -value for the test could be greater or less than 0.05. It can't be determined without knowing the sample size.
2. The distribution of times that a company's service technicians take to respond to trouble calls is Normal with mean μ and standard deviation σ = 0.25 hours. The company advertises that its service technicians take an average of no more than 2 hours to respond to trouble calls from customers.
From a random sample of 25 trouble calls, the average time service technicians took to respond was 2.10 hours. How strong is the evidence against the company's claim? Based on these data, the P -value of the appropriate test is
A. less than 0.0002.
B. 0.0228.
C. 0.0456.
3. The times for untrained rats to run a standard maze has a N (65, 15) distribution where the times are measured in seconds. The researchers hope to show that training improves the times. The alternative hypothesis is
A. Ha: µ > 65.
B. Ha: x' > 65.
C. Ha: µ < 65.