Identify the null Hypothesis,
alternative hypothesis, test statistic, P-value, conclusion about null
hypothesis, and final conclusion that address the original claim.

Various temperature measurements
are recorded at different times for particular city. The mean of 20 C is
obtained for 40 temperatures on 40 different days. Assuming the standard
deviation = 1.5 C, test the claim that the population mean is 22 C. Use a 0.05
significance level.