Interpret a scatter diagram.
1. Describe the relationship between the hours each student of a school spends in after school jobs each week and their grade average.
Hours (x): {20, 13, 9, 6, 2, 15, 10, 5, 1}
Grade average (y): {60, 65, 70, 80, 90, 68, 73, 85, 90}
a) Fairly strong positive association
b) Fairly weak positive association with clusters
c) Fairly strong negative association
d) Weak association because it is negative
e) None of the above
2. Given SAT Math and SAT Verbal scores for each student of a school, determine if there is a linear relationship between SAT Math and Verbal scores. Justify your answer.
SAT Math (x): (660, 700, 720, 450, 520, 600, 660, 580, 550)
SAT Verbal (y): (600, 650, 580, 480, 520, 530, 610, 600, 550, 520)
a) No, the residual plot reveals a pattern
b) No, there is weak relationship -r2 is less than .90.
c) Yes, ther is a very strong relationship because as the Math scores increases so do the verbal
d) Yes, a fairly strong relationship -r = .87 and there is no pattern in the residual plot