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

Use the above information to answer questions 1-10.

_____ 1) The study design is

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

_____ 2) What numbers are being compared in the test?

                  a) average difference and zero    b) means     c) standard deviations    d) critical values

_____ 3) Which number from the computer output is compared to the significance level     

                  to check if the null hypothesis should be rejected?

                  a) degrees of freedom    b)   test statistic      c) P-value         d) critical value

_____ 4)   What type of conclusion error could be made using the results of this study?

                 a) type II                b)   none            c) type III                            d) type I

_____ 5) 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

_____ 6) Would there be a statistically significant difference between the means if the   

                significance level were set at .01?

                a) yes                       b) no               c) if it was a one-tail test     d) not enough info

_____ 7) List the p-value if a two-tailed test was run.

                a) .031                     b) .95                 c) .062                              d) .0001

_____ 8) Which number from the output shows the predetermined probability of a type-I error.

                a) significance level        b)   test statistic        c) critical value    d) P-value

_____ 9) Have you proven that one razor is better that the other?

                a) no                                  b) yes                      c) not enough info    d) depends on p-value

_____10) What unit of measure does the 1.978 represent? ____________________________

Answer 1

Solution:

Using the given information in the problem we give the answer for following questions