Sample annual salaries​ (in thousands of​ dollars) for employees at a company are listed.
41  54  61  48  27  27  41  54  61  31  48  41  47
​(a) Find the sample mean and sample standard deviation.
​(b) Each employee in the sample is given a 5​% raise. Find the sample mean and sample standard deviation for the revised data set.
​(c) To calculate the monthly​ salary, divide each original salary by 12. Find the sample mean and sample standard deviation for the revised data set.
​(d) What can you conclude from the results of​ (a), (b), and​ (c)?