12. Testing Laboratory Gloves The New York Times ran an article about a study in which Professor Denise Korniewicz and other Johns Hopkins researchers subjected laboratory gloves to stress. Among 240 vinyl gloves, 63% leaked viruses. Among 240 latex gloves, 7% leaked viruses. See the accompanying display of the Minitab results. Using a 0.005 significance level, test the claim that vinyl gloves have a larger virus leak rate than latex gloves.

p Treatment Group Placebo Group n1
500 n2
400 x1
100 x2
50 Males Females n1
1068 n2
1220 x1
332 x2
420 TI-83/84 Plus Minitab 9-2 Inferences About Two Proportions 465