below is the sales experience(in months) and the number of computers sold the the previous month of seven sales people.

Question

Experience 4 12 9 6 10 30 7
Sales 19 42 28 31 39 30 21
Using the Minitab info write the straight line(least squares) equation and the correlation coefficent.
The regression equation is:
sales=27.2+0.252 exp
Predictor Coef SECoef T P
Constant 27.195 5.781 4.70 0.005
Exp. 0.2517 0.4201 0.60 0.575
S=8.97833 R-sq=6.7%

Answer 1

I ran your data through an online calculator and the regression equation looks correct. See below:

7 data pairs (x,y):
( 4.00 , 19.0 ); ( 12.0 , 42.0 ); ( 9.00 , 28.0 ); ( 6.00 , 31.0 ); ( 10.0 , 39.0 ); ( 30.0 , 30.0 ); ( 7.00 , 21.0 );

y = a + bx where:
a= 27.2
b= 0.252

Correlation coefficient:

r = 0.259 (p = 0.575)