The method of least squares was used to t a straight line mo

The method of least squares was used to ?t a straight line model to these
data. The equation of the least squares ?t line is
y = 98.7 + 0.971x.
(a) Choose more meaningful labels for the explanatory and dependent
variables, and hence write down an equation that may be used to
model the relationship between a person

Solution

a. Let replace y by BP (blood presure) and x by AY (age )

so model become

BP=98.7+.971AY

b. BP=98.7+.971 x 45

BP=142.395

BP=142.40 (approx.)

c. difference in BP of A and B= 5x.971

=4.86

because model is linear so BP also changes linearly.

(98.7+.971(x+5)-(98.7+.971 x)= 5 (.971)=4.86)