What is the common difference for the sequence shown below?
points at (-1, 2), (1, 3), and (3, 4)
a. -2
b. -1/2
c. 1/2
d. 2

we can always find the slope of any line by simply using two points on the line, say let's  use (3,4) and (-1,2)

option 1

data plot with   3 dots over 33, 1 dot over 34, 2 dots over 35, no dot over 36, 1 dot over 37, 2 dots over 38, 4 dots over 39, and 2 dot over 40.