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.

Question

Shaded region is 92 how would I find the z-score to a negative decimal after dividing it?

Answer 1

You can find the raw score that corresponds to the area 0.92, in desmos, by entering normaldist(100,15).inversecdf(0.92). This will give you a score of 121.076.

Input this score, into the formula

z = x - μ = 121.076 - 100 = 1.4051

σ 15

So your z-score is -1.4051