252grass4 041 3 29 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 Pelosi and Sandifer 20 Employees A T are timed in a computer entry task initially 0hr after 2 hours of work 2hr after 4 hours 4hr and after 6 hours 6hr The times in seconds are reported below a At a 5 significance level do the four mean times differ b determine which of the times actually differ c On the basis of these data how would you react to a proposal that employees only be allowed to work for four hours a day at this task Only neat and legible papers with written answers in complete sentences will be read 0 Hours 67 64 69 88 72 80 85 116 77 78 68 51 54 75 71 64 86 98 103 91 2 Hours 84 78 74 91 70 73 86 71 76 76 61 62 94 63 70 63 66 71 53 81 4 Hours 52 53 56 66 59 77 64 62 54 65 71 92 71 50 71 58 77 53 81 70 6 Hours 57 53 71 61 73 50 53 80 63 41 63 41 53 63 61 46 68 64 49 70 Do this problem in Excel as follows Use columns A B C D E and F on the Excel spreadsheet for data In the first row of Columns B C D and E put in 0hr 2hr 4hr and 6hr Head column A with the word employee Starting in Cell A2 Put in the letters A through T to identify the employees unless of course you want to suggest some names Now put in the data in columns B C D and E skipping column A 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 F in cell F2 write B2 after your enter this cell should read 67 Use the edit pull down menu and copy cell F2 Use the edit pull down menu and paste in cells F3 through F21 Now column F will be identical to B except for the heading This can also be done as a simple copy and paste Save your data as time1 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 E 21 Select New worksheet ply and columns check labels in first row hit OK and save your results as treslt1 xls Version B Two way ANOVA In orderto 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 E 21 check labels and save your results as treslt2 xls Answer the following Is there a significant difference between the task completion times according to the number of hours worked How is this conclusion affected by blocking by employees 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 time1 xls To fill column B this time in cell B2 write F2 x replacing x with the last digit of your social security number Use the edit pull down menu and copy cell B2 Use the edit pull down menu and paste in cells B3 through B21 Now column B will be more than the original B by the amount of your value of x Save your data as time3 xls Run the one way ANOVA again and save your results as treslt3 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 24 6 possible differences between means and report which are different at the 5 level according to each of the 2 methods Now on the basis of these data how would you react to a proposal that employees only be allowed to work for four hours a day at this task Why 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 20 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 Thr the following Minitab commands print c1 c5 AOVO c2 c5 You should get results equivalent to your first ANOVA To set up for a 2 way ANOVA stack your data in columns 6 and 7 Stack c2 c3 c4 c5 c6 Subscripts c7 UseNames To move the row labels copy the A through T from column 1 Highlight all 80 cells of column 8 and paste your A T into the column Every number should now have a correct row label Use the material from computer assignment 2 to check your data I combined the ANOVA and the table of means command by using the following Twoway c6 c8 c7 Means c8 c7 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 c5 Unstacked To do the tests on the stacked data use the following Vartest c6 c7 2 Extra Extra Credit Do Bartlett and Levene tests using the examples in 252mvar as your pattern It turns out that your ANOVA has just enough columns to do this test 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 Bartlett test you need logarithms of variances Label Columns 10 12 …
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