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A random variable X has a probability density function  (n is an integer) with mean 3. The values of {k, n} are

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  4. {1, 2}

Answer (Detailed Solution Below)

Option 3 :
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Detailed Solution

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Concept: 

If f(x) is probability density function, then

1.

2. Mean

Calculation:

X has a probability density function f(x)

We know that,

 → (1)

Given that mean = 3

 

 → (2)

From equations (1) and (2)

We know that 

⇒ 3n! = (n + 1)!

⇒ 3 = n + 1

⇒ n = 2

From equation (1),

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