21.31 Estimating unemployment. The Bureau of Labor Statistics (BLS) uses 90% confidence in presenting unemployment results from the monthly Current Population Survey (CPS). The September 2015 survey reported that of the 156,715 individuals surveyed in the civilian labor force, 148,800 were employed and 7915 were unemployed. The CPS is not an SRS, but for the purposes of this exercise, we will act as though the BLS took an SRS of 156,715 people. Give a 90% confidence interval for the proportion of those surveyed who were unemployed. (Note: Example 3 in Chapter 8 on page 166 explains how unemployment is measured.)