A psychologist is conducting a study to determine whether there are differences between the ability of history majors and mathematics majors to solve various types of puzzles. Five mathematics majors and five history majors were randomly selected from the students at a liberal arts college in Maine. Each student was given the same five different puzzles to complete: a crossword puzzle, a cryptogram, a logic problem, a maze, 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 a 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. Plot the mean time to complete a puzzle for each puzzle type by major. What conclusion would you reach about the interaction between major and puzzle type?
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 a puzzle for history majors depends on the type of puzzle. Does the mean time to complete a puzzle for mathematics majors depend on the type of puzzle?
Conduct the one-way ANOVA tests at a level of significance of 0.05.