ABSTRACT
A sample of 200 products is taken, and 3 products have been identified as defective. Figure 4.1 shows how to select “1 Proportion” in Minitab® to test the population proportion of defectives. Doing so will open the dialog box shown in Figure 4.2. Enter “3” for “Number of events” and “200” for “Number of trials”. Also, check the box for “Perform hypothesis test” and enter “0.05” for “Hypothesized proportion”. Click on “Options” and the dialog box shown in Figure 4.3 opens. Select “less than” from the drop-down menu for “Alternative” and click on “OK”. This takes you back to the dialog box shown in Figure 4.2. Click on “OK” and the output shown in Figure 4.4 is the result. Because P-value (0.012) is less than 0.05, reject the null hypothesis. In other words, the population proportion of defectives is lower than 5%, which is good news.
