Question

In a statistics course, a linear regression equation was computed to predict the final exam score from score on the midterm exam. The equation of the least squares regression line was

Y = 10 + 0.9x

Where y represents the final exam score and x is the midterm exam score. Suppose Joe score a 90 on the midterm exam.

What would be the predicted value of his score on the final exam?

a. 81
b. 89
c. 91
d. cannot be determined from the information given. We also need to know the correlation.

Answer 1

The correct option would be 'c. 91'

Explanation:

Given equation that shows the predicted final exam score,

`y = 10 + 0.9x`

Where,

x = midterm exam score,

If midterm exam score is 90,

i.e. x = 90,

Then the predicted value of his score on the final exam is,

`y = 10 + 0.9(90) = 10 + 81 = 91`

Hence, OPTION C is correct.

Answer 2

Answer: c. 91

Explanation:

Given : A linear regression equation was computed to predict the final exam score from score on the midterm exam.

The equation of the least squares regression line was

`Y = 10 + 0.9x`

, where y= the final exam score

x= the midterm exam score.

if Joe score a 90 on the midterm exam, the put x= 90 in the above eqaution , we get

`Y = 10 + 0.9(90)`

`\Rightarrow\ Y = 10 + 81=91`

Hence, the predicted value of his score on the final exam would be 91.

Therefore , the correct answer is c. 91 .