A study was conducted to compare two different procedures for assembling components. Both procedures were implemented and run for a month to allow employees to learn each procedure. Then each was observed for 10 days with the following results. Values are number of components assembled per day.
Procedure I 115 101 113 64 104 97 114 96 87 93
Procedure II 86 99 100 78 97 111 102 94 88 99
Construct a 98% con?dence interval for the difference in the mean number of compo- nents assembled by the two methods. Assume that the data for each procedure are from approximately normal populations with a common variance. Interpret the result.