Question

Twelve standard lengths of wool were extended over a given load before and after washing. The (after-lessbefore) differences (cm) in the extensions were 1.7,−0.3,0.3,0.9,−0.4,2.4,1.1,0.5,1.2,0.7,−0.5,1.4

Test whether or not washing increases extensibility in general, at 5% significance using the critical region method.

Answer 1

Here critical value = 1.7959

Test statistic. t= 2.9297

The null hypothesis rejected since test statistic is larger than 1.7959