The mean income per year of employees who produce internal andexternal newsletters and magazines for corporations was reported tobe $76300. These editors and designers work on corporatepublications but not on marketing materials. As a result of pooreconomic conditions and oversupply, these corporate communicationsworkers may be experiencing a decrease in salary. A random sampleof 40 corporate communications workers revealed that x? = $73000.Conduct a hypothesis test to determine whether there is anyevidence to suggest that the mean income per year of corporatecommunications workers has decreased. Assume that the populationstandard deviation is $6360. Please use the exact value (from R)for all critical values.

Test statistic = -3.2816

P-value = 0.0005160833

a. Calculate the appropriate 99% bound that is consistent with aone-sample z-test.

b. Interpret the bound calculated above.

c. If the employer also found a cheaper medical insurance thatreduced the amount of money that the employees have to pay forhealth insurance by $1000 per year, in practical terms, are theemployees really taking home less money than before? Please explainyour answer.

d. Explain why parts the test statistic and p-value state thesame thing as the calculated bound. That is, what in the first partis consistent with the second part.