How much of an increase in height (X-Value) is associated with an increase in Weight (Y-Value).
- average height =70 inches (x Value)
- average weight = 70 inches (y Value)
- Height SD = 3
- Weight SD = 15
- R=.40
If height is one SD above average how much will the weight be above average?
70 (Ave Height) + 3 (1 SD) = 73
- 180 (Ave Weight) + 45 (1 SD) x .40 (r) = 18,
- 18 +180 = 198 LBS
1.5 SD in Height
Height = 70 + 4.5 (3 x 1.5 SD) = 74.5
REMEMBER TO ALWAYS MULTIPLY r by SD value of X. So (R x 1.5 =.60). Than Multiply by Y SD
180 (Ave Weight) + 45 (1 SD) x .60
(r=.4 x 1.5) = 27,
27 +180 = 207 LBS
Height is -2 SD
Height = 70 - 6 (3 x -2 SD) = 63
- 180 (Ave Weight) - 45 (SD) x .80 (r=.4 x 2) = 36,
- 36 - 180 = 144 LBS
[(SU of x)] x (r) +or- (Ave)]