In a study published in the journal Teaching of Psychology, the article “Fudging the Numbers:
Distributing Chocolate Influences Student Evaluations of an Undergraduate Course” states that distributing chocolate to students prior to teacher evaluations increases results. The authors randomly divided three sections of a course taught by the same instructor into two groups. Fifty of the students were given chocolate by an individual not associated with the course and 50 of the students were not given chocolate.
The mean score from students who received chocolate was 4.2, while the mean score for the nonchocolate group was 3.9. Suppose that the sample standard deviation of both the chocolate and nonchocolate group was 0.8. Does chocolate appear to improve teacher evaluations? Use the α = 0.1 level of significance.