Question 1019231
I fit the equation using EXCEL.
.
.
.
*[illustration cf1.JPG].
.
.
.
If you know it's a straight line, you can determine the equation using any two points.
First find the slope.
{{{m=(y[2]-y[1])/(x[2]-x[1])=(130-50)/(5-1)=80/4=20}}}
Now use any point and the slope using the point-slope form of a line,
{{{y-y[1]=m(x-x[1])}}}
{{{y-50=20(x-1)}}}
{{{y-50=20x-20}}}
{{{highlight(y=20x+30)}}}
This was done using point 1 and point 6. 
You can verify that each of the other points is also on the line.
Example point 2,
{{{y=20(1.5)+30}}}
{{{y=30+30}}}
{{{y=60}}}
({{{1.5}}},{{{60}}})
You would need to do this for the remaining points to verify that they are also on the line.
Or you could generate six lines and show that the slope and y-intercept are identical.