linear regression?

Question

City: A,B,C...J
No. of commercials,x
Sales Units,y

A; x:12; y: 7
B; x: 6; y: 5
C; x: 9; y: 10
D; x: 15; y: 14
E: x:11; y: 12
F; x: 15; y: 9
G; x: 8, y: 6
H; x: 16; y: 11
I; x: 12; y: 11
J; x: 6; y: 8

i) Find the least squares regresion line for the data
ii) Calculate the correlation coefficient n coefficient of determination. Interpret the results with respect to the data.
iii) Estimate the sales units when x=20

Answer 1

I could do this problem but why should I?

If you have a TI-83 calculator it is a very easy problem to do. If you don't you just have to accumulate the right sums and apply the equations.