In the following regression, Y is the number of words recalled, X 1 is the amount of time spent studying the list, and X 2 is the time since the study period ended. In an experiment with 20...

In the following regression, Y is the number of words recalled, X₁
is the amount of time spent studying the list, and X₂
is the time since the study period ended. In an experiment with 20 participants, you obtain the following regression printout:

(a) Is there significant evidence that at least one of the independent variables is linearly related to Y?

(b) Your research partner states, “For each additional minute of time since the study period ended, words recalled is expected to decrease by 2.16 words.” Is this statement correct? If not, reword it.

(c) The values of X₁
ranged from 1 to 3 minutes, and the values of X₂
ranged from 1 to 4 minutes. Produce a plot that illustrates the effects of the independent variables on the predicted value of Y, using typical low and high values for each.

(d) Your research partner states, “A person given 2 minutes of study time and 3 minutes since the study period ended is highly likely to have a number of words recalled between 9.50 and 18.34.” Check your partner’s statement as best you can given this information. Is the statement reasonable?