According to a recent poll 28% of adults in a certain area have high levels of c

Question

According to a recent poll 28% of adults in a certain area have high levels of cholesterol. They report that such elevated levels could be financially devastating to the regions healthcare system" and are a major concern to health insurance providers. According to recent studies, cholesterol levels in healthy adults from the area average about 205 mg/dL, with a standard deviation of about 35 mg/dL, and are roughly Normally distributed. If the cholesterol levels of a sample of 46 healthy adults from the region is taken, answer parts (a) through (d). (a) What is the probability that the mean cholesterol level of the sample will be no more than 205? Pys205)- (Round to four decimal places as needed) (b) What is the probability that the mean cholesterol level of the sample will be between 200 and 2103? P(200 y

Explanation / Answer

mean is 205 and s is 35

for sample size of 46, the standard error is SE=s/sqrt(N)=35/sqrt(46)=5.16

z is (ybar-mean)/SE

a) P(ybar<205)=P(z<(205-205)/5.16)=P(z<0)=0.5

b) P(200<ybar<210)=P((200-205)/5.16<z<(210-205)/5.16)=P(-0.97<z<0.97) or 2*P(z<0.97)-1

from normal distribution table we get 2*0.8340-1=0.668

c) P(ybar<195)=P(z<(195-205)/5.16)=P(z<-1.94) or 1-P(z<1.94)=1-0.9738=0.0262

d) P(ybar>217)=P(z>(217-205)/5.16)=P(z>2.32) or 1-P(z<2.32)=1-0.9898=0.0102

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

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