Mental Health Estimates of the prevalence of Alzheimer\'s disease have recently
ID: 3057021 • Letter: M
Question
Mental Health Estimates of the prevalence of Alzheimer's disease have recently been provided by Pfeffer et al. [8]. The estimates are given in Table 3.5. Suppose an unrelated 77-year-old woman, 76-year-old man, and 82- year- old man are selected from a community Table 3.5 Provalence of Atzhelmers disease (cases per 100 population 65-69 70-74 75-79 80-84 1.8 4.9 8.6 35.0 2.2 2.3 2L8 27.9 a. Suppose we know one of the three people has Alzheimer's disease, but we don't know which one. What is the conditional probability that the affected persón is a woman? b. Suppose we know one of the three people has Alzheimer's disease, but we don't know which one. What is the conditional probability that the affected person is a woman? c. Suppose we know two of the three people have Alzheimer's disease. What is the conditional probability that they are both men?Explanation / Answer
77 year old woman = 2.3
76 year old man = 4.9
82 year old man = 8.6
a)
P (woman) = 2.3/(2.3+4.9+8.6) = 0.1456
b)
Same as above as the question is same
c)
P(both men) = (4.9*8.6)/(4.9*8.6+2.3*4.9+2.3*8.6) = 0.57