Question

(a) Find the​ least-squares

regression

line treating number of absences as the explanatory variable and the final exam score as the response variable.

ModifyingAbove y with caret

equalsnegative 2.688xplus88.378

​(Round to three decimal places as​ needed.)

​(b) Interpret the slope and the​ y-intercept, if appropriate. Choose the correct answer below and fill in any answer boxes in your choice.

​(Round to three decimal places as​ needed.)

A.

For every additional​ absence, a​ student's final exam score drops

2.688

​points, on average. The average final exam score of students who miss no classes is

88.378

.

Your answer is correct.

B.

For every additional​ absence, a​ student's final exam score drops

nothing

​points, on average. It is not appropriate to interpret the​ y-intercept.

C.

The average final exam score of students who miss no classes is

nothing

.

It is not appropriate to interpret the slope.

D.

It is not appropriate to interpret the slope or the​ y-intercept.

​(c) Predict the final exam score for a student who misses five class periods.

ModifyingAbove y with caret

equals74.94

​(Round to two decimal places as​ needed.)

Compute the residual.

​(Round to two decimal places as​ needed.) looking for residual?

Answer 1

(a) Find the​ least-squares regression

The 'x' is the number of absences and the dependent variable 'y' is the final score.

Comparing with the basic equaltion we have

y -intercept = 88.378

This is the value when x= 0 or that there are no absence, the score would be 88.378.

Slope = -2.688

This value shows the degree of change in y due to a change in 'x'. Since it is negative, a unit increase in 'x' will lead to decrease in 'y' by 2.688

​(b) Interpret the slope and the​ y-intercept, if appropriate. Choose the correct answer below and fill in any answer boxes in your choice.

= 88.378

. = -2.688

A. For every additional​ absence, a​ student's final exam score drops

2.688

​points, on average. The average final exam score of students who miss no classes is

88.378

​(c) Predict the final exam score for a student who misses five class periods.

We have five misses and we need to predict the final score. So we just substitute in the reg eq x = 5

= 88.378 - 2.688 *5

Compute the residual.

Residual is the error or the difference between the actual and estimated value.

Orignally when x = 5 , 'y' had to be some value.

Therefore residual = (when x = 5)