Question

According to a poll done in 2010, 58 % of adults aged 25-29 had only a cell phone (no landline). Assume that two randomly selected adults (aged 25-29) are asked whether they have only a cell phone. The probability that one of the adults has only a cell phone is ?

Answer 1

Given: p = 0.58, q = 1 - p = 0.42, n = 2 formula: P(X = x) = n/x C* P^x * q^n - 1 n/xC = n!/x!(n - x)! P(X = 1) = 2/1 C * 0.58^1 * 0.42^1 P(X = 1) = 2!/1!(2 - 1)! * 0.58^1 * 0.42^1 P(X = 1) = 2 * 0.58^1 * 0.42^1 P(X = 1) = 0.4872

$P(X=1)=2*0.58^{1}*0.42^{1}$

$P(X=1)={\color{Red} \mathbf{0.4872}}$