Question

A survey was done to compare the salaries of network administrators in two areas of the city, the northern and southern regions. An independent random sample of 300 network administrators was selected from each of the two regions by asking their annual salaries. Sample mean, Northern Region - 102300, Southern Region - 98500. Sample standard deviation, Northern Region - 5700, Southern Region - 3800. Construct a 99% confidence interval of μ1- μ2 the difference in the mean salaries.