A baseline analysis was conducted on an epidemiological study that included 20,0

Question

A baseline analysis was conducted on an epidemiological study that included 20,000 individuals. This analysis focused on the prevalence of high blood pressure and on the prevalence of smoking, two known risk factors for coronary artery disease (CAD). The following were some of the results: 15% had high blood pressure and were smokers, given that someone is a smoker there is a 38% chance of them having high blood pressure, and 50% of the 20,000 individuals had high blood pressure or smoked.

a. Let A be the event that an individual that participated in this study was a smoker. Determine P(A) the probability of event A.

b. Let B be the event that an individual that participated in this study had high blood pressure. Determine P(B), the probability of event B.

c. How many of the 20,000 individuals that participated in this study neither had high blood pressure nor were smokers at baseline?

Explanation / Answer

a)here P(high blood pressure|smoker) =0.38 also P(high blood pressure and were smokers)=0.15

P(high blood pressure|smoker) =P(high blood pressure and were smokers)/P(smoker)=0.38

P(smoker) =P(A) =0.15/0.38 =0.3947

b) P(B) =P(A U B)+P(A n B) -P(A) =0.50+0.15-0.3947=0.2553

c) probability that participant in this study neither had high blood pressure nor were smokers at baseline

=1-P(A U B) =1-0.50 =0.50

hence individuals individuals that participated in this study neither had high blood pressure nor were smokers at baseline =0.5*20000 =10000

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

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