A study was conducted to explore the relationship between women's age (X) and muscle mass (Y) after the age of 40. A total of 46 women between the ages of 41 and 78 were sampled. The mean age was 59.98 and the sample variance was 139.17.

We are interested to test whether the population mean age () is different from 65 years at the 5% level of significance.

State the null and alternative hypotheses.