In a statistics course, a linear regression equation was computed to predict the final exam score from the score on the first test. The equation was y = 10 +.9x where y is the final exam score and x is the score on the first test. Carla scored 95 on the first test. On the final exam, Carla scored 98. What is the value of her residual?

2.5

Step-by-step explanation:

The predicted regression equation is

y^=10+0.9x

where y = final exam score and x=first test score.

Also, we are given that Carla's final exam score y is 98 and Carla's first test score x is 95. We have to find residual for Carla.

Residual=Observed - predicted=y-y^

y^=10+0.9x

We know that Carla's first test score=x=95.

So,

y^=10+0.9 (95)

y^=10+85.5

y^=95.5

Residual for Carla=y-y^=?

We know that Carla's final exam score=y=98.

So,

Residual for Carla=98-95.5=2.5