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

Was a right, left, or two-tailed test run to support Gillett’s claim?

                 a) left                     b) right               c) two-tailed                     d) not enough information

Answer 1