According to Stats Canada, 12% of Canadian adults have high levels of cholestero

Question

According to Stats Canada, 12% of Canadian adults have high levels of cholesterol. Recent study shows that total cholesterol levels in healthy adults are roughly following N(192,41) [unit is mg/dL]. We now collected cholesterol levels from 50 healthy Canadian adults. a) If your cholesterol level is 226, what is your position (in%) from the top? b)If the poll is correct, what is the cut-off point for high cholesterol? c) Describe the sampling distribution for the sample mean. d) What is the probability that the sample mean will be more than 200? e) If the sample size was increased to 100, how would you expect the sampling distribution to change?

Explanation / Answer

Ans:

Given that

mean=192

standard deviation=41

a)

z(226)=(226-192)/41=0.829

P(Z>0.829)=0.2035 or 20.35%

you are in top 20.35%

b)P(Z>z)=0.12

P(Z<=z)=1-0.12=0.88

z=1.175

cut off=192+1.175*41=240.175

c)sampling distribution of sample means:

mean=192

standard deviation=41/sqrt(50)=5.80

d)

z=(200-192)/5.8=1.38

P(z>1.38)=0.0838

e)mean=192

standard deviation=41/sqrt(100)=4.1

b)

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.