Answer:
a) 15.58
b) 39.06
Step-by-step explanation:
MENSA is organization whose member have IQs in the top 2% of the population. IQs are normally distributed with mean 100, and the minimum IQ score required for admission to MENSA is 132.
From standard normal table z value for top 2% =2.054
132 = 100+2.054×σ
σ=(132-100)/2.054=15.58
(b) Cholesterol levels for women aged 20 to 34 follow an approximately normal distribution with mean 185 milligrams per deciliter (mg/dl). Women with cholesterol levels above 220 mg/dl are considered to have high cholesterol and about 18.5% of women fall into this category.
From standard normal table z value for top 18.5% =0.896
220 = 185+0.896×σ
σ=(220-185)/0.896 =39.06