Usually, I always look for the y intercept first! This one is -4, since that's where the line hits the y axis. From that point, you would use RISE/RUN to find the slope, and in this case, it's 3/5 !!
<span>3 is 1.0 below the mean. That is 1.0 / 0.9, or 1.1111... standard deviations below the mean. So look up z < -1.11 on your graphing calculator. It should be around 0.1335 or 13.35%</span>