. A business researcher wants toestimate the average number of years of experience an accountmanager has working with the company before getting promoted toaccount manager. Eight account managers are randomly selected andasked how long they worked with the company before becoming anaccount manager. The resulting answerswere:     1.2, 4.0, 3.6, 0.7, 5.8, 3.3, 2.8,4.1

      Use Excel and these data tocompute a 90% confidence interval to estimate the average length oftime an account manager spent working for the company before theywere promoted to account manager. Print out your answer.

      Directions:

For most current versions of Excel,go to the Data tab, selectData Analysis, and DescriptiveStatistics. Enter the input range. Check off that you wantSummary Statistics and Confidence Intervalfor the mean. Enter the value of the level of confidence.In the output you will get several things. The value of themean is the point estimate. The value labeled“confidence level” is actually the + error of theinterval. The “error of the interval” already has the table valueof t and the standard error of the mean computed withinit. Use the mean and the “error of the interval” to make theconfidence interval. You will probably have to manually type thisout somewhere on the spreadsheet or cut and paste it together inExcel and printout the confidence interval.