Chapter: Probability Distributions· Mathematics & Statistics (Commerce) Part 2

Three coins are tossed simultaneously. \(X\) is the number of heads. Then the expected value of \(X\) is ____.

Q.4 (A)(vi) Three coins are tossed simultaneously. \(X\) is the number of heads. Then the expected value of \(X\) is ____.

A. 1

B. 1.5

C. 1.9

D. 1.017

Doubtly Asked 29 Oct 2026 Board exam · July 2024 hsc 12th Save WhatsApp Report

1 answer

Best answer

Answer: (b) 1.5

\(X \sim B(n = 3, p = \frac{1}{2})\), so \(E(X) = np = 3 \times \frac{1}{2} = 1.5\). (Directly: \(0 \cdot \frac{1}{8} + 1 \cdot \frac{3}{8} + 2 \cdot \frac{3}{8} + 3 \cdot \frac{1}{8} = \frac{12}{8} = 1.5\).)

Doubtly AI · 29 Oct 2026 AI-verified · Nov 2026 Report

Was this answer helpful?

Three coins are tossed simultaneously. \(X\) is the number of heads. Then the expected value of \(X\) is ____.

1 answer

Your answer