Confidence Intervals and One-sample T-test using SPSS for Windows

(Moore and McCabe Problem 6.107 using s not σ)

1. Go to START /All Programs / SPSS for Windows.

2. SPSS will initially put you into a NEW DATA screen with a line of commands and toolbar at the top. Enter the data Dimethyl Sulfide values for wine in one column

    32

    33

    40

    35

    24

    36

    31

    30

    20

    25

 If you make a mistake, use the mouse to click on the cell (or arrows to return to the cell) and simply change the value. If you want to name the variable, click on the VARIABLE VIEW Tab at the bottom and give it a name, eg., dms. When you are done entering data, select FILE/SAVE AS and save the data into your jump drive or on the desktop temporarily -- mm6_75.sav. The extension .sav indicates it is a data file that can ONLY be read by SPSS.

2. To look at the distribution of the variable dms look at a stemplot or boxplot with ANALYZE/ DESCRIPTIVE STATISTICS / EXPLORE and highlight the variable dms and click on the > to move it over. You can choose different statistics or plots than the defaults by clicking on the appropriate box and selecting options from the new screen. Then select OK and SPSS will run and examine the output.

3. To have SPSS construct a confidence interval, use ANALYZE / COMPARE MEANS / ONE SAMPLE T TEST and move over dms to TEST VARIABLE and check under OPTIONS to see if the confidence coefficient is what you want. The default is 95%. Then click OK and examine the output.

4. To have SPSS do a one sample t-test vs. a hypothesized value , use ANALYZE / COMPARE MEANS / ONE SAMPLE T TEST and move over dms to TEST VARIABLE and enter the TEST VALUE if different than zero. Then click OK and examine the output.

5. To print the output, choose Print under File. SPSS wastes paper, so several pages are printed for each procedure so be careful what you print. You can save the SPSS output file with the SAVE AS command under File, but name with a .spo extension so that you know it is output and not a data file. For example, you could save the output from the scores data onto your jumpdrive as E:mm6_107.spo or you can go to FILE/EXPORT as and save it as a doc file and take it home and print it.  But PRINT PREVIEW first to make sure it looks ok on the 8 1/2 x 11 inch paper.  Sometimes SPSS decides to save to custom sized paper.