The random variable X has a probability distribution P(X) of the following from where k is a scalar and $P(X=x)= \left\{\begin{matrix}k, & if & x=0\\2k, & if & x=1\\3k, & if & x=2\\0, & & otherwise \end{matrix}\right.$ then value of P(X< 2) = __________. |
$\frac{5}{6}$ $\frac{3}{4}$ 1 $\frac{1}{2}$ |
$\frac{1}{2}$ |
Given $P(X=0)=k,\;P(X=1)=2k,\;P(X=2)=3k$ Total probability $=1$ $k+2k+3k=6k=1$ $k=\frac{1}{6}$ Now $P(X<2)=P(X=0)+P(X=1)$ $=k+2k=3k$ $=3\cdot\frac{1}{6}$ $=\frac{1}{2}$ The value of $P(X<2)$ is $\frac{1}{2}$. |