Question: Test the given claim using the traditional method of hypothesis testing. Assume that the sample has been randomly selected from a population with a normal distribution.

A researcher wants to check the claim that convicted burglars spend and average of 18.7 months in jail. She takes a random sample of 11 such cases from court files and finds that X=21.1 months and s=7 months. Test the null hypothesis that m=18.7 at the 0.05 significance level