Assume that a psychologist conducted a study to determine whether there are differences

between the ability of history majors and mathematics majors to solve various types of

puzzles. Twenty-five mathematics majors and 25 history majors were randomly selected

from the students at a liberal arts college in Maine. Five students from each major were

randomly assigned one of the following puzzles: a crossword puzzle, a cryptogram, a

logic problem, a maize and a cross sums. The time in minutes (rounded to the nearest

minute) was recorded for each student in the study. If a student could not complete

puzzle in the maximum time allowed, or completed a puzzle incorrectly, then a penalty of

10 minutes was added to his or her time. The results are shown in the file Puzzle.

a) Using a line graph, plot the mean time to complete puzzle for each type by major.

b) At the 0.05 level of significance, is there an interaction effect?

c) If interaction is present, conduct a one-way ANOVA to test whether the mean time to

complete puzzle for history majors depends on the type of puzzle. Does the mean time

to complete puzzle for mathematics majors depends on the type of puzzle? Conduct the

one-way ANOVA tests at a level of significance of 0.05.