Question

Number of Absences
Final
Grade

0
93

1
93

2
77

3
68

4
65

5
54



- Find the correlation coefficient for the data.
I got this part of my answer. I believe the answer to be -0.9767
I am just going crazy with the second part.

- Find the equation for the regression line for the data, and predict the final grade of a student who misses 3.5 days.

Thanks :)

Answer 1

Using an online calculator, I found the following:

6 data pairs (x,y):
( 0.00 , 93.0 ); ( 1.00 , 93.0 ); ( 2.00 , 77.0 ); ( 3.00 , 68.0 ); ( 4.00 , 65.0 ); ( 5.00 , 54.0 );

r = -0.977 (rounded to 3 decimal places)

Equation for the regression line:
predicted y = 95.6 - 8.23x

Substitute 3.5 for x in the regression equation to calculate y.

I hope this will help.