Question

You are given the following data.
Number of Absences Final
Grade
0 95
1 91
2 82
3 69
4 67
5 58


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

Answer 1

Using an online calculator, I have the following:

6 data pairs (x,y):
( 0.00 , 95.0 ); ( 1.00 , 91.0 ); ( 2.00 , 82.0 ); ( 3.00 , 69.0 ); ( 4.00 , 67.0 ); ( 5.00 , 58.0 );

r = -0.987 -->correlation coefficient

predicted y = 96.3 - 7.71x -->regression equation

To find the final grade of a student who misses 3.5 days, substitute that value for x and solve for predicted y.

I hope this will help.