Find the area of the shaded region. The graph to the right depicts IQ scores of adults, and those scores are normally distributed with a mean of 100 and a standard deviation of 15.

The Z-score measure how many standard deviations are there in an x value taken from the mean. In this, the given is 5 units out from the 105. 5 is 1/3 of the standard deviation, based from the table of z-scores, z of 105 will be equals to 0.3333, while 20 units is 1/3 of 80, the standard deviation will be z of 80 will be - 1.33333