The Professor's Response
I don't know if I don't understand it or its just that I've been all day doing problems, but I don't know how to do D. Can you help me please?? :)
I plugged an entire class of 200 into SPSS in order to calculate the least squares line for the entire data set. The results were as follows: y^ = 0.512 x + 70.196 .
a) What does x = 0 represent here?
b) What is the expected grade for students who do not earn any clicker points?
c) What is the average grade for a student who has 20 clicker points?
d) I pulled the grade and clicker points for a randomly chosen student from a different class of statistics from the spring term 2010. That student had 35 clicker points and a 94% in the class. Plug 35 points into our model, and determine the prediction error for this case.
See the professor's answer below.