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A random variable X has the following probability distribution:

X2345
P(X)5/k7/k9/k11/k

Then the value of k4\frac{k}{4} is:

Solution

✅ Correct Option: 1

For any probability distribution, all probabilities must add up to 1.

From the table:

P(X=2)=5kP(X = 2) = \frac{5}{k}

P(X=3)=7kP(X = 3) = \frac{7}{k}

P(X=4)=9kP(X = 4) = \frac{9}{k}

P(X=5)=11kP(X = 5) = \frac{11}{k}


All probabilities sum to 1:

5k+7k+9k+11k=1\frac{5}{k} + \frac{7}{k} + \frac{9}{k} + \frac{11}{k} = 1

Since all fractions have the same denominator:

5+7+9+11k=1\frac{5 + 7 + 9 + 11}{k} = 1

32k=1\frac{32}{k} = 1


32k=1\frac{32}{k} = 1

32=k32 = k

Therefore k=32k = 32


k4=324\frac{k}{4} = \frac{32}{4}

k4=8\frac{k}{4} = 8

Therefore, the value of k4\frac{k}{4} is 88.

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