On a graph with pressure / 105 Pa units, with a y axis that goes up in 0.5s and an x axis that goes across in 20, you have a graph line stretching from 1.3 (0 on y axis) to 1.8 (140 on a y axis), what is the gradient to 3 significant figures?

I got 93.3 x 10 but I know I am wrong. Can someone explaine where I went wrong?