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{Exercise 4.45 (Algorithmic)} In an article about investment alternatives, Money

ID: 3068986 • Letter: #

Question

{Exercise 4.45 (Algorithmic)}

In an article about investment alternatives, Money magazine reported that drug stocks provide a potential for long-term growth, with over 50% of the adult population of the United States taking prescription drugs on a regular basis. For adults age 65 and older, 80% take prescription drugs regularly. For adults age 18 to 64, 45% take prescription drugs regularly. The age 18–64 age group accounts for 86.6% of the adult population (Statistical Abstract of the United States, 2008).

Round your answers to 4 decimal places.

a. What is the probability that a randomly selected adult is 65 or older?

b. Given an adult takes prescription drugs regularly, what is the probability that the adult is 65 or older?

{Exercise 4.45 (Algorithmic)}

In an article about investment alternatives, Money magazine reported that drug stocks provide a potential for long-term growth, with over 50% of the adult population of the United States taking prescription drugs on a regular basis. For adults age 65 and older, 80% take prescription drugs regularly. For adults age 18 to 64, 45% take prescription drugs regularly. The age 18–64 age group accounts for 86.6% of the adult population (Statistical Abstract of the United States, 2008).

Round your answers to 4 decimal places.

a. What is the probability that a randomly selected adult is 65 or older?

b. Given an adult takes prescription drugs regularly, what is the probability that the adult is 65 or older?

Explanation / Answer

Solution:

Given that

P(takes prescription drugs/>=65) = 0.80

P(takes prescription drugs/18-64) = 0.45

P(18-64)= 0.866

P(takes prescription drugs)= 0.80*(1-0.866)+0.45*0.866 = 0.4969

a) P(>=65) = 1-0.866 = 0.134

b) P(>=65/takes prescription drugs)=P(takes perscription drugs/>=65)*P(>=65)/P(takes perscription drugs)

= 0.80*0.134/0.4969 = 0.2157