Question

Gillette claims that their double-edge shaver is better than the leading brand of single-edge shavers (Lady Bic). In a recent study, 26 women rated the Gillette and the Lady Bic shavers on smoothness, closeness and safety. One group of women were used and each woman recorded two scores. The mean difference of those scores were tested with the following results.

                                                         

Critical Value…………… t = 1.645

Test statistic ..................... t = 1.978

P-value..............................   =   . 031

Significance level ……........... =   .05

The study design is

           a) pre-test/posttest        b) one-sample dependent mean     c) two-sample mean

Answer 1

From the given information the data was collected from 26 women and each women recorded two scores, and then mean difference of these two scores is tested,

Here sampled data is dependent or matched pair data becouse two observation from one individual are taken in two time points.

Hence study design used is

Pre test/ post test study,

Also called as paired test.