Strack, Martin, and Stepper XXXXXXXXXXreported that people rate cartoons as funnier when holding a pen in their teeth (which forced them to smile) than when holding a pen in their lips (which forced...

Strack, Martin, and Stepper (1988) reported that people rate cartoons as funnier when holding a pen in their teeth (which forced them to smile) than when holding a pen in their lips (which forced them to frown).  A researcher attempted to replicate this result using a sample of n = 25 adults between the ages 40 and 45. For each person, the researcher recorded the difference between the rating obtained while smiling and the rating obtained by frowning. On average, the cartoons were rated funnier when the participants were smiling, with an average difference of M D = 1.6 with SS = 150.

In this problem, you do not have to calculate SS or the mean difference which is already provided.

Do the data indicate that the cartoons are rated significantly funnier when the participants are smiling?  Use a one-tailed test with α = .05

Problem solving template

1. Compute test statistic (Repeated measure t-score)

            Variance  for D scores: S²

                        Estimated standard error S_MD
 :

                        Computed repeated measure t statistic:

2. Make a decision about the null hypothesis and state a conclusion.

      Decision: Are you going to reject the null or fail to reject the null

      Conclusion:  ex. The independent variable did or did not have a significant effect

      Remember: if you reject, there was significance