If x is the first number in the sequence, you can represent the next consecutive number using (x+1), the one after with (x+2), etc. We can set up an equation like this:
x + (x+1) + (x+2) + (x+3) = 130
This can be simplified to:
4x + 6 = 130
Now subtract 6 from each side:
4x = 124
Next we divide each side by 4:
x = 31
We have the first number in the sequence, but we need the THIRD number. Since we've already established that (x+2) would be the third number, we can just plug in x.
