Purdue STAT 30100: Elementary Statistical Methods Project # 2 Summer II 2015

Q2. Too much cholesterol in the blood increases the risk of heart disease. Young women are generally

less afflicted with high cholesterol than other groups. The cholesterol levels of women aged 20 to 34

follow an approximately normal distribution with mean 180 milligrams per deciliter (mg/dl) and

standard deviation 35 mg/dl. What percent of young women have cholesterol levels between 210 and

245 mg/dl?

Part A: Answer the question

(i) Formulate the problem (define the random variable, state the parameters and write an appropriate

probability statement) [3 pts.]

ii) Sketch an appropriate normal distribution curve and shade the area under the curve that corresponds to

this question in (i) [1 pt.]

iii) Convert the x variable into z-value. [3 pts.]

iv) Put z-value on the sketch in (ii), (z below x ) [1 pt.]

v) Use Standard Normal Table to find the desired probability. [2 pts.]