stat analysis homework and excel lab

DS 123 – Lab Assignment # 4

Chaffe-Stengel, Fall 2016

Hypothesis tests: t-tests of two population means, equal & unequal variances

1. Read Problem 10.12 on page 390. Assuming the auto loan rates are independently sampled and normally distributed, conduct 5-part formal hypothesis tests side-by-side, on the left in the t-statistic and on the right in the p-value, to test whether the mean rates for the 48-month fixed and variable-rate auto loans differ. Use  = 0.05.

To add the JMP output for Problem 10.12:

a. Open JMP.

b. File – New – Data Table.

c. Column 1 enter Fixed in cells 1 – 8, Variable in cells 9 – 13.

d. Rename column 1 Types of Rates.

e. Go back to the Excel spreadsheet. Copy fixed rate values from Excel. On JMP table, double click on column 2 cell 1, Control-V to paste the eight values.

f. Go back to the Excel spreadsheet. Copy variable rate values from Excel. On JMP table, paste the values in column 2 cells 9 – 13.

g. Rename column Rates.

h. Highlight Rates title, select Col-Column info. In the window, format – Dec should show 2, not 0. Click OK.

i. Analyze-Fit Y by X.

j. Move Rates to Y, Response. Move Types of Rates to X, Factor. Click OK.

k. Click the red diamond next to Oneway Analysis. Select Means/Anova/Pooled t.

l. ALT-Edit-Copy.

m. Go back to the Excel spreadsheet. In cell J2, paste the JMP report. Delete material in cells J40:O72.

n. From the JMP report, right click on the Oneway Analysis graphic. Edit-Copy graph.

o. On the Excel spreadsheet, paste the graph with the upper left corner located on M9.

p. From the JMP report, right click on the t-Test assuming equal variances graphic. Edit – Copy graph.

q. On the Excel spreadsheet, paste the graph with the upper left corner located on cell N24.

2. A local bank ran a spot advertising campaign on their 30-year fixed-rate home mortgage. Branch A is located in a large shopping mall anchored by a department store and produced a sample of 14 randomly selected applications for home mortgage loans shown below during the advertising campaign. Branch B is located in a shopping mall anchored by a national grocery chain and produced a sample of 16 randomly selected applications for home mortgage loans shown below during the advertising campaign. Use the unequal variances t-test to test whether there was any difference in the average amounts of home mortgages applied for at the two branches. Use  = 0.05.

To add the JMP output for question 2:

a. Open JMP.

b. File – New – Data Table.

c. Column 1 enter Branch A in cells 1 – 14, Branch B in cells 15 – 30.

d. Rename column 1 Branches

e. Go back to the Excel spreadsheet. Copy Branch A loan values from Excel. On JMP table, double click on column 2 cell 1, Control-V to paste the fourteenvalues.

f. Go back to the Excel spreadsheet. Copy Branch B loan values from Excel. On JMP table, paste the values in column 2 cells 15 – 30.

g. Rename column Loans.

h. Analyze-Fit Y by X.

i. Move Loans to Y, Response. Move Branches to X, Factor. Click OK.

j. Click the red diamond next to Oneway Analysis. Select t-Test.

k. ALT-Edit-Copy.

l. Go back to the Excel spreadsheet. In cell J47, paste the JMP report.

m. From the JMP report, right click on the t-Test assuming unequal variances graphic. Edit – Copy graph.

n. On the Excel spreadsheet, paste the graph with the upper left corner located on cell N54.

This assignment is due October 3.