Question

The following data give the height in inches (X) and the weight in lb. (Y) of a random sample of 10 students from a large group of students of age 17 years:

X	61	68	68	64	65	70	63	62	64	67
Y	112	123	130	115	110	125	100	113	116	125

Estimate weight of the student of a height 69 inches.

Answer 1

 

\(\bar{Y}=\frac{1169}{10}\) = 116.9

Regression equation of Y on X 

Y - \(\bar{Y}=b_{yx}(X-\bar{X})\)

Y – 117 = 2.3479 (X – 65.2)

Y – 117 = 2.3479X – (2.3479)(65.2)

Y = 2.3479X – 153.08308 + 117 

Y = 2.3479 – 36.08308 

When the height X = 69 inches 

Weight, Y = 2.3479(69) – 36.08308 

= 162.0051 – 36.08308 

= 125.92202 

= 125.92 lb