statistics check
posted by tracy12 on .
The computerscience aptitude score, x, and the achievement score, y (measured by a comprehensive final), were measured for 10 students in a beginning computerscience course. The results were as follows. (Give your answers correct to two decimal places.)
x 7 10 19 9 20 22 6 13 18 15
y 29 27 28 33 24 15 25 23 21 18
(a) Find the equation of the line of best fit.
y hat = 0.56 + 1.78 x
(b) Find se2.
36.00

Y hat = .57x + 32.20

So what did I do wrong on the part b? That one is wrong also.

What Do you mean se2

What Do you mean by this se2

I am sorry that is Se squared. That is the way it is written on the test.

SE² is given by:
[ Σ(yyBar)^2  [Σ(xxBar)(yyBar)]²/Σ(xxBar)² ] /(n2)
I get:
Σ(yyBar)²=258.1
Σ(xxBar)(yyBar) = 168.7
Σ(xxBar)²=296.9
n=10
to get
se²=20.28 
I have a question where did you get 258.1. I must of had my numbers wrong, because I had those other two.

I got it from summing (yyBar)^2, and I had yBar=24.3.

Ok, thank you, I had the wrong numbers for the yBar

You're welcome!