Let X be random variable which assumes $x_1, x_2, x_3, x_4$ such that $2P(X=x_1)= 3P(X=x_2)=P(X=x_3)=5P(X=x_4)$, then the probability distribution of X is |
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The correct answer is Option (4) **
Given: $2P(X=x_1)=3P(X=x_2)=P(X=x_3)=5P(X=x_4)$ Let the common value be $k$. $2P(X=x_1)=k \Rightarrow P(X=x_1)=\frac{k}{2}$ $3P(X=x_2)=k \Rightarrow P(X=x_2)=\frac{k}{3}$ $P(X=x_3)=k$ $5P(X=x_4)=k \Rightarrow P(X=x_4)=\frac{k}{5}$ Total probability = $1$ $\frac{k}{2}+\frac{k}{3}+k+\frac{k}{5}=1$ $k\left(\frac{15+10+30+6}{30}\right)=1$ $k\left(\frac{61}{30}\right)=1$ $k=\frac{30}{61}$ Thus, $P(X=x_1)=\frac{k}{2}=\frac{15}{61}$ $P(X=x_2)=\frac{k}{3}=\frac{10}{61}$ $P(X=x_3)=k=\frac{30}{61}$ $P(X=x_4)=\frac{k}{5}=\frac{6}{61}$ The probability distribution is: $(\frac{15}{61},\frac{10}{61},\frac{30}{61},\frac{6}{61})$. |