A random variable X has the following probability distribution:
The value of $P(4 <x<7)$ is equal to |
$\frac{3}{100}$ $\frac{1}{2}$ $\frac{5}{100}$ $\frac{7}{100}$ |
$\frac{3}{100}$ |
The correct answer is Option (1) → $\frac{3}{100}$ Given probability distribution: $X: 0,1,2,3,4,5,6,7$ $P(X): 0, k, 2k, 2k, 3k, k^{2}, 2k^{2}, 7k^{2}+k$ Sum of probabilities is $1$. $k+2k+2k+3k+k^{2}+2k^{2}+(7k^{2}+k)=1$ $9k+10k^{2}=1$ $10k^{2}+9k-1=0$ $k=\frac{-9+\sqrt{81+40}}{20}=\frac{-9+11}{20}=\frac{1}{10}$ Required probability: $P(4<\text{ X }<7)=P(5)+P(6)$ $=k^{2}+2k^{2}=3k^{2}$ $=3\left(\frac{1}{10}\right)^{2}=\frac{3}{100}$ Final answer: $\frac{3}{100}$ |