Test Hypotheses About a Population Mean with Known Using Confidence $22.4$

Test Hypotheses about a Population Mean with Known Using Confidence Intervals
-A group of 49 randomly selected construction workers has a mean age of $22.4$ years with a standard deviation of $3.8$ . According to a recent survey, the mean age should be $\mu = 21.9$ years. Test this hypothesis by constructing a $98 \%$ confidence interval for the population mean.