A set of n = 15 pairs of scores (X and Y values) produces a correlation of r = 0.40 . If each of the ...

A set of n = 15 pairs of scores (X and Y values) produces a correlation of r = 0.40 . If each of the X values is multiplied by 2 and the correlation is computed for the new scores, what value will be obtained for the new correlation?
 
  a. r = 0.20
  b. r = 0.40
  c. r = 0.80
  d. Cannot be determined without knowing all the X and Y scores

Question 2

Suppose the correlation between height and weight for adults is +0.40 . What proportion (or percent) of the variability in weight can be explained by the relationship with height?
 
  a. 40 c. 16
  b. 60 d. 84

Question 3

A set of n = 5 pairs of X and Y scores has X = 15, Y = 5, and XY = 10 . For these data, what is the value of SP?
 
  a. 5 c. 10
  b. 5 d. 25

Question 4

A set of n = 10 pairs of scores has X = 20, Y = 30, and XY = 74 . What is the value of SP for these data?
 
  a. 74 c. 14
  b. 24 d. 14