Answer:
a)
b) 
c)
Step-by-step explanation:
Data given
x: 500, 700, 750, 590 , 540, 650, 480
y: 7.00, 7.50 , 9.00, 6.5, 7.50 , 7.0, 4.50
Part a
We want to create a linear model like this :

Wehre
And:
With these we can find the sums:
And the slope would be:
Nowe we can find the means for x and y like this:
And we can find the intercept using this:
And the line would be:
Part b
The correlation coefficient is given by:
For our case we have this:
n=7
The determination coefficient is given by:

Part c