DSCI 3321 - Spring 2017 Computer Assignment - 3 Due on Wednesday, April 26, 2017 for Section 07 Due on Thursday, April 27, 2017 for Sections 01 and 02 1. A business researcher wants to estimate the average number of years of experience an account manager has working with the company before getting promoted to account manager. Eight account managers are randomly selected and asked how long they worked with the company before becoming an account manager. The resulting answers were: 1.2, 4.0, 3.6, 0.7, 5.8, 3.3, 2.8, 4.1 Use Excel and these data to compute a 90% confidence interval to estimate the average length of time an account manager spent working for the company before they were promoted to account manager. Print out your answer. Directions: For most current versions of Excel, go to the Data tab, select Data Analysis, and Descriptive Statistics. Enter the input range. Check off that you want Summary Statistics and Confidence Interval for the mean. Enter the value of the level of confidence. In the output you will get several things. The value of the mean is the point estimate. The value labeled \"confidence level\" is actually the + error of the interval. The \"error of the interval\" already has the table value of t and the standard error of the mean computed within it. Use the mean and the \"error of the interval\" to make the confidence interval. You will probably have to manually type this out somewhere on the spreadsheet or cut and paste it together in Excel and printout the confidence interval. 2. Construct a 98% confidence interval to estimate the average value of \"Annual Food Spending\" in the Consumer Food Database that has been loaded into WileyPLUS. You will find this under Read, Study & Practice. Look for \"Excel Database\" at the top of the page. Once the Excel database file opens, find the tab of the database for which you are looking at the bottom of the Excel page. Use the same steps as those discussed in question 1 to find the answer. 3. Hypothesis Tests of single samples cannot be directly computed using Excel. In order to get Excel to do them, we must \"trick\" Excel. Work Demonstration Problem 9.2 (page 322), section 9.3, of the text using Excel. Directions: Enter the data in the spreadsheet. If you want, you can label the column as Sample 1. Since you are testing a hypothesis that the mean is 471, you can trick Excel into doing this one-sample t test by entering 471 as all the values in Sample2 in another column. Since there are 23 data points in this problem, you will have to enter 23 values of 471 in this second column. Now go to the Data tab and then Data Analysis in Excel. Select t-Test Two-Sample: Assuming Equal Variances. Place the location of the data in the box labeled Variable 1 Range. Place the location of the constant hypothesized value (column containing the 471) in the box labeled Variable 2 Range. Place \"0\" under hypothesized mean difference. Put in the value of alpha. In this case, it is .05 and Excel defaults to .05 so leave it as it is