IS 242 Exam #3 name: _________________________________ Question ONE: XXXXXXXXXXfirst second third Total cooks XXXXXXXXXX XXXXXXXXXX XXXXXXXXXX 23.33 XXXXXXXXXX 0.476 cleaning XXXXXXXXXX 75 XXXXXXXXXX...

Exam 3 questions for Business Stats


IS 242 Exam #3name: _________________________________ Question ONE: first second third Total cooks 25 30 20 75 26.67 25.00 23.33 0.104 1.000 0.476 cleaning 35 20 20 75 26.67 25.00 23.33 2.604 1.000 0.476 Waiters 20 25 30 75 26.67 25.00 23.33 1.667 0.000 1.905 Total 80 75 70 225 Chi-Sq = 9.232, DF = 4, P-Value = 0.056 A researcher is interested in whether or not a significant trend exists regarding the popularity of certain work shifts among her employees: cooks, cleaning, and wait-staff. A random sample of 75 from each job category is selected. The responders are asked to indicate which of three work shifts they preferred. The results are given above for each shift by job category. Do the results deviate significantly from what would be expected due to chance? Show your work. Explain your answer. Question TWO: 3000 on campus apartments are available for newly enrolled students. Of the 10,000 students enrolled 85% are from the state “resident” and 15% are listed as “non-resident”. You want to know if an equal portion of incoming resident and non-resident students newly enrolled request on campus housing. Write the null and alternate hypothesis. Ho: Ha: Question THREE: Given the mean height of centennial rose bushes is µ feet and the standard deviation is σ feet: write the null and alternative hypotheses you would test to answer whether the mean height for all centennial rose bushes is now more than 4 feet. Ho: Ha: Question FOUR: Your printer has skipped – you are to fill in the missing values on the chart below:             source DF SS MS F P factor 1 326780 error 773135 total 29 1099916             Question Five: List the Assumptions for Linear Regression State whether a linear model is appropriate for based on the Residual Plots below. (Explain in detail why/why not). Question Six: You have been asked to complete an analysis of the usefulness of a model your company uses to predict response Y . Write the Regression Equation based on the computer output below: _______________________________________________________________________ Which factors you would recommend to use in a future model (how you determined your decisions). Variable(s) to include (because): _______________________________________________________(__________________________) Computer Output coefficients Coef SE Coef T P Constant -0.17411 0.280769 -0.6201 0.541 x1 0.01341 0.011839 1.1327 0.269 x2 0.00943 0.077509 0.1216 0.904 x3 -0.00900 0.008385 -1.0733 0.294 x4 -0.02557 0.011660 -2.1930 0.038 x5 1.18277 0.106958 11.0583 0.000 Summary of Model S = 0.425899 R-Sq = 89.98% R-Sq(adj) = 87.89% PRESS = 6.94315 R-Sq(pred) = 84.02% Analysis of Variance Source DF Seq SS Adj SS Adj MS F P Regression 5 39.0853 39.0853 7.8171 43.095 0.000000 x1 1 6.7154 0.2327 0.2327 1.283 0.268518 x2 1 1.5073 0.0027 0.0027 0.015 0.904228 x3 1 0.6103 0.2090 0.2090 1.152 0.293808 x4 1 8.0710 0.8723 0.8723 4.809 0.038238 x5 1 22.1813 22.1813 22.1813 122.285 0.000000 Error 24 4.3534 4.3534 0.1814 Total 29 43.4387 Fits and Diagnostics for Unusual Observations Obs y Fit SE Fit Residual St Resid 23 -0.8 0.0672037 0.174444 -0.867204 -2.23199 R Question Seven: A clothing manufacturer MineRgoods has asked you to set up a control chart to determine, based on the number of defects per garment, if their sewing process is in control. You have collected the following data. Run the appropriate control chart(s) in Minitab and write your conclusion and recommendation for MineRgoods. Sample number of IDDefects 124 228 336 447 523 626 729 845 948 1032 1145 1256 1358 1441 1525 1638 1721 1829 1938 2032 2145 2242 2326 2438 2545 Question Eight: A home canner manufacturer is interested in learning if people would choose the canner they purchased again. So the manufacturer does a survey 700 of their most recent customers and found the following data. Use an alpha of 0.05 to test whether the data shows a difference among the three canner types. Choose Again Canner A Canner B Canner C Total Yes 128 199 186 No 88 33 66 Total Explain your test statistic, result, and business conclusion. Question Nine: You work for a package delivery company and wish to determine if your process is in control or if you need to make changes to the system. You recommend ________________ explain Question Ten: When testing Ho: µ = 16 versus H1: µ does not equal 16 at a .05 level of significance, the p-value  computed is .001, then the decision is:   a. Reject Ho b. Accept Ho c. Fail to reject Ho d. Not determinable from the information provided True or False The focus of total quality management is the prevention of defects _________________ 4002000-200-400 99 90 50 10 1 Residual P e r c e n t 800600400200 200 0 -200 Fitted Value R e s i d u a l 2001000-100-200-300 4.8 3.6 2.4 1.2 0.0 Residual F r e q u e n c y 30282624222018161412108642 200 0 -200 Observation Order R e s i d u a l Normal Probability PlotVersus Fits HistogramVersus Order Residual Plots for value