A survey of wage scales for workers of comparable skill levels was conducted in different regions of the country. In the sample of 500 office workers in the Northeast, the average hourly wage was $ 11.84, with standard deviation of $ 1.23. In the Southeast, a sample of 400 office workers showed an average of $ 9.48, with standard deviation of $ 2.04. Construct the appropriate 90% confidence interval estimate of the overall difference in average hourly wage for the population of office workers in the two regions.