Question

38. Suppose you have a random variable X with: X: 3, 6, 9, 12; $P(X = 3) = 0.2$, $P(X = 6) = 0.2$, $P(X = 9) = 0.3$, $P(X = 12) = 0.3$. (a) Compute E[X]. (b) Compute E[$X^2$]. (c) Hence, find Var(X).

Name: 38 suppose you have a random variable x with x 3 6 9 12 px 3 02 px 6 02 px 9 03 px 12 03 a compute ex b compute ex2 c hence find varx 79564
Uploaded: 2025-01-29T17:39:03-08:00
Duration: 2 min 15 s
Channel: Sheryl Ezze
Description: 38 suppose you have a random variable x with x 3 6 9 12 px 3 02 px 6 02 px 9 03 px 12 03 a compute ex b compute ex2 c hence find varx 79564

          38. Suppose you have a random variable X with:
X: 3, 6, 9, 12; $P(X = 3) = 0.2$, $P(X = 6) = 0.2$, $P(X = 9) = 0.3$, $P(X = 12) = 0.3$.
(a) Compute E[X].
(b) Compute E[$X^2$].
(c) Hence, find Var(X).

Added by Anthony D.

Elementary Statistics a Step by Step Approach

Allan G. Bluman 9th Edition

Instant Answer

Solved by Expert Sheryl Ezze

01/29/2025

Step 1

$E[X] = \sum_{i} x_i P(X = x_i) = 3(0.2) + 6(0.2) + 9(0.3) + 12(0.3) = 0.6 + 1.2 + 2.7 + 3.6 = 8.1$ Show more…

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38. Suppose you have a random variable X with: X: 3, 6, 9, 12; $P(X = 3) = 0.2$, $P(X = 6) = 0.2$, $P(X = 9) = 0.3$, $P(X = 12) = 0.3$. (a) Compute E[X]. (b) Compute E[$X^2$]. (c) Hence, find Var(X).