What is the moment generating function for an exponential distribution?

What is the moment generating function for an exponential distribution?

• A. M(t) = 1/(1-θt)
• B. M(t) = 1/(1-λt)
• C. M(t) = 1/(1-θt^2)
• D. M(t) = θ/(θ - t)

Answer: (A)

The moment generating function (MGF) for a random variable is a tool used to encapsulate all of its moments (such as mean and variance) in a single function. For the exponential distribution, which is commonly defined with parameter λ (the rate parameter), the MGF is derived from the definition of the MGF itself, which is given by the expected value of e^(tX), where X is the random variable. The MGF for the exponential distribution with rate parameter λ is computed as follows: 1. The probability density function (PDF) of the exponential distribution is f(x) = λe^(-λx) for x ≥ 0. 2. The moment generating function M(t) can be computed as: - M(t) = E[e^(tX)] = ∫ from 0 to ∞ e^(tx) * λe^(-λx) dx - M(t) = λ ∫ from 0 to ∞ e^((t - λ)x) dx 3. The integral converges for t < λ, which simplifies to: - M(t) = λ / (λ - t), for t < λ. This expression, M(t) = λ / (

The moment generating function (MGF) for a random variable is a tool used to encapsulate all of its moments (such as mean and variance) in a single function. For the exponential distribution, which is commonly defined with parameter λ (the rate parameter), the MGF is derived from the definition of the MGF itself, which is given by the expected value of e^(tX), where X is the random variable.

The MGF for the exponential distribution with rate parameter λ is computed as follows:

1. The probability density function (PDF) of the exponential distribution is f(x) = λe^(-λx) for x ≥ 0.

2. The moment generating function M(t) can be computed as:

• M(t) = E[e^(tX)] = ∫ from 0 to ∞ e^(tx) * λe^(-λx) dx

• M(t) = λ ∫ from 0 to ∞ e^((t - λ)x) dx

3. The integral converges for t < λ, which simplifies to:

• M(t) = λ / (λ - t), for t < λ.

This expression, M(t) = λ / (