Q1) Instructor asked 5 students how many hours they had studied for the exam. For part vi, suppose that hours studied is predictor variable. Here are number of hours and student's grades:
|
Hours studied
|
Test Grade
|
|
0
|
52
|
|
10
|
95
|
|
6
|
83
|
|
8
|
71
|
|
6
|
64
|
i) Create a scatter diagram of the raw scores.
ii) Explain in words the general pattern of association.
iii) Figure the correlation coefficient.
iv) Descrbe the logic of what you have done, writing as if you were speaking to someone who has never had a statistics course, but who does understand the mean, standard deviation, and Z scores.
v) Give 3 logically possible directions of causality, saying for each whether it was reasonable direction in light of variables involved and explain why.
vi) Create raw score predictions on criterion variable for persons with Z scores on predictor value of -2,-1,0,+1,+2
vii) Write down the proportion of variance accounted for R (2) (little 2)