For children between the ages of 18 months and 29 months the

For children between the ages of 18 months and 29 months, there is approximately a linear relationship between “height” and “age”. The relationship can be represented by: Y = 64.93 + 0.63(X), where Y represents height (in centimeters) and X represents age (in months). Joseph is 22.5 months old and is 80 centimeters tall. What is Joseph’s residual (e)?

a.
64.93
b.
+0.9
c.
-0.9
d.
79.1
e.
56.6

Solution

Answer . b +0.9

For (22.5 , 80)

y = 64.93 + 0.63 * 22.5 = 79.105

Thefore,

Residual = 80 - 79.105 = +0.9 Answer b