Question 250627
We have coordinates here: (75, 301) and (1,5).
To find the common difference, we need the slope formula:
{{{(Y2 - Y1) / (X2 - X1)}}}
Putting in our X,Y coordinates, we get
{{{(301-5)/(75-1)}}}
which is 
296/74 = 4.
The common difference is 4.