Discussion:
Q: Suppose that you wish to test a researcher's claim that the mean of a normally distributed population has increased from its commonly accepted value of 1.60. In order to carry out this test, you obtain a random sample size of 150 from this population. This sample yields a mean of 1.80 and a standard deviation of 1.30. What are the appropriate null and alternative hypothesis? Is this a one-tailed or two tailed test?