Need answer with calculation!

Question 6 (15 pts). We are interested in the mean age of a certain population. A random sample of 12 individuals drawn from the population of interest has a mean of 32. Assuming that the population is approximately normally distributed with variance 25, can we conclude that the mean is different from 40 years based on a test with a = 0.05? If the pvalue is 0.04 how can we use it in making a decision