Question

. It is found that 40% of american victims of health care fraud are senior citizens. if 19 victims are randomly selected, find the probability that at most 8 are senior citizens

Answer 1

X ~ B(19, 0.4)
X ~ N(19 x 0.4, 19 x 0.4 x 0.6)
X ~ N(7.6, 4.56)
P(X ≤ 8) = P(z ≤ (8 - 7.6)/4.56) = P(z ≤ 0.0877) = 0.5349