252grass4 072 10 08 07 Open this document in Page Layout view Name Student Number Class days and time Please include this on what you hand in Graded Assignment 4 The data set is part of a problem due to Groebner et al 14 Testers were sent out to 3 branches of a Mexican fast food chain Store 1 3 Though the order of the visits was random each tester visited each store once They rated the restaurant on a number of characteristics and their ratings were totaled and shown Only neat and legible papers with written answers in complete sentences will be read Make sure that you have access to a copy of Excel with statistical functions enabled To enable statistical functions enter Excel and use the Tools pull down menu Select Add Ins and check Analysis Tool Pack and MegaStat This is available in Anderson Tester 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Str 1 830 743 652 885 814 733 770 829 847 878 728 693 807 901 Str 2 647 840 747 639 943 916 923 903 760 856 878 990 871 980 Str 3 630 786 730 617 632 410 727 726 648 668 670 825 564 719 Do this problem in Excel as follows Use columns A B C D and E on the Excel spreadsheet for data In the first row of Columns B C and D put in Str1 Str2 and Str3 Head column A with the word Tester Starting in Cell A2 Put in the letters 1 through 14 to identify the testers unless of course you want to suggest some names Now put in the data in columns B C and E skipping column D If you bring this document into Word the data can be moved into the Excel worksheet by highlighting the cells you want and copying and pasting To fill column D in cell D2 write E2 After your enter this cell should read 630 Use the edit pull down menu and copy cell D2 Use the edit pull down menu and paste in cells E3 through E14 or use handle on lit up cell Now column D will be identical to E except for the heading This can also be done as a simple copy and paste Save your data as rating1 xls Version A One way ANOVA Use the tools pull down menu and pick data analysis If you cannot find this use Tools and Add Ins to put in the analysis packs Pick ANOVA Single Factor Set input range to B 1 D 15 Select New worksheet ply and columns check labels in first row hit OK and save your results as rreslt1 xls Version B Two way ANOVA In order to check for the effect of the fact that the data is blocked by employees repeat the analysis using ANOVA Two Factor without replication Set input range to A 1 D 14 check labels and save your results as rreslt2 xls Answer the following Is there a significant difference between the store ratings How is this conclusion affected by blocking by testers Cite p values and or F tests Version C One way ANOVA Take the last digit of your student number if it s zero use 10 Go back to your original data or use the file pull down menu to open rating1 xls To fill column D this time in cell D2 write E2 x replacing x with the last digit of your student number Use the edit pull down menu and copy cell D2 Use the edit pull down menu and paste in cells D3 through D14 Now column D will be more than the original D by the amount of your value of x Save your data as rating3 xls Relabel the column as Str 3yy where yy is 01 10 depending on what you added to the column Run the one way ANOVA again and save your results as rreslt3 xls Submit the data and results with your Student number The most effective way to do this is to paste the results into a Word document and then add neat hand or typed notes Indicate what hypotheses were tested what the p value was and whether using the p value you would reject the null if i the significance level was 5 and ii the significance level was 10 explaining why You will have two answers for each of your two problems For your Version C do a Scheffe confidence interval and a Tukey Kramer interval or procedure for each of the C 23 3 possible differences between means and report which are different at the 5 level according to each of the 2 methods Extra Credit 1 Show that you learned something from computer problem 2 by doing part B on Minitab There should be very little difference in your result The easiest way to do this is to copy the first five columns from the original Excel spreadsheet Enter Minitab and use editor to enable commands Highlight the column labels and cells 1 14 of the first five columns Remember that your column labels should be written in above the columns Put row labels in column 1 Just to make sure that you are in the right place Try the following Minitab commands print c1 c4 AOVO c2 c4 Tukey 5 Fisher 5 You should get results equivalent to your first ANOVA but with individual and Tukey intervals done for you To set up for a 2 way ANOVA stack your data in columns 11 and 12 Stack c2 c3 c4 c11 Subscripts c12 UseNames To move the row labels copy the labels from column 1 to column 13 Label column 11 13 Rating Store and Tester1 Every number should now have a correct row label Use the table commands from computer assignment 2 to check your data I combined the ANOVA and the table of means command by using the following Twoway c11 c13 c12 Means c13 c12 2 Take the data from your last ANOVA Use the instructions in 1 above to copy it into the Minitab spreadsheet and perform Levene and Bartlett tests on it using the third example in 252mvarex as a pattern for your calculations using Minitab Make sure that you explain what is being tested and what you conclude There are two ways to do this If you want to do it on the unstacked data use the following Vartest c2 c4 Unstacked To do the tests on the stacked data use the following Save and layout your graphs Vartest c11 c12 You should also test the columns for Normality The Lilliefors test for column 2 would be the following NormTest c2 KSTest Now answer the following What requirements must your individual columns meet for ANOVA to be valid What evidence do you have that these requirements were met Extra Extra Credit Do Bartlett and Levene tests by hand using the examples in 252mvar as your pattern This is an awful lot of work unless you cheat and use the computer If you cover your tracks I ll never know To do the …
View Full Document
Unlocking...