Answer to Question #203836 in Statistics and Probability for Jelay

Question

Let D represet the defective cellphone and N the non-defective

Answer 1

Suppose three cell phones are tested randomly. We want to find out the number of defective cellphones that occur.

Let $D$ represent the defective cellphone and $N$ represent the non-defective cellphone. If we let $X$ be the random variable representing the number of defective cell phones, can you show the values of random variable $X$?

$\def\arraystretch{1.5} \begin{array}{c:c} Possible & Value \ of\ the \\ outcomes & random \ variable\ X \\ \hline NNN & 0 \\ NND & 1 \\ NDN & 1 \\ DNN & 1 \\ NDD & 2 \\ DND & 2 \\ DDN & 2 \\ DDD & 3 \\ \end{array}$

$X\in\{0, 1, 2, 3\}$

Probability distribution

$\def\arraystretch{1.5} \begin{array}{c:c} x & 0 & 1 & 2 & 3 \\ \hline p(x) & 1/8 & 3/8 & 3/8 & 1/8 \end{array}$