Question: Twelve students were rated on the extent of their class participation, with a value of 0 assigned to someone who never talks and a value of 7 to a student who frequently participates in class discussions. The same people also were rated on an extravert-introvert (E-I) scale, with a score of 0 for a person who is quiet and shy (introvert) and up to a score of 5 for a person who is outgoing (extravert). Determine whether there is any relationship between extraversion-introversion and class participation. Compute the correlation three ways.

a. Assume the ratings on participation and extraversion are interval-level data.

b. Assume the ratings are only valid as ordinal-level measurement.

c. Compute the Pearson correlation on the rankings of the data and compare all three results. Test your answers for significance, and tell what your decision means in the context of the exercise.