2025/2026 | Portage Learning | Verified
Questions and Answers | A+ Graded
Section 1: Introduction
This document provides the verified exam content for Module 4 of MATH 110 – Statistics
from Portage Learning, fully updated for the 2025/2026 academic year. It includes 100%
correct answers to questions covering discrete probability distributions, binomial probability,
and expected value. Graded A+ and aligned with Portage Learning’s online curriculum, this
guide offers essential support for success in introductory statistical coursework.
Section 2: Exam Questions and Answers
Format: Multiple-choice and problem-based questions
Four answer choices per question (A–D)
Correct answer highlighted
Includes brief explanations for key terms and concepts
Question 1
Question: What is a discrete probability distribution?
A) A distribution with continuous outcomes
B) A distribution with countable outcomes
C) A uniform distribution
D) A skewed distribution
B) A distribution with countable outcomes
Explanation: Discrete distributions have distinct, separate values.
Question 2
Question: What is the expected value of a random variable X with P(X=1) = 0.5, P(X=2) =
0.3, P(X=3) = 0.2?
A) 1.7
B) 2
C) 2.1
D) 2.5
A) 1.7
Explanation: E(X) = (1×0.5) + (2×0.3) + (3×0.2) = 0.5 + 0.6 + 0.6 = 1.7.
Question 3
Question: In a binomial distribution, what does "n" represent?
A) Number of trials
B) Probability of success
C) Number of failures
D) Expected value
, A) Number of trials
Explanation: n is the fixed number of independent trials.
Question 4
Question: What is the probability of exactly 2 successes in 4 trials if p = 0.5?
A) 0.25
B) 0.375
C) 0.5
D) 0.625
B) 0.375
Explanation: P(X=2) = C(4,2) × (0.5)² × (0.5)² = 6 × 0.25 × 0.25 = 0.375.
Question 5
Question: Which condition is NOT required for a binomial distribution?
A) Fixed number of trials
B) Two outcomes per trial
C) Independent trials
D) Continuous outcomes
D) Continuous outcomes
Explanation: Binomial requires discrete outcomes.
Question 6
Question: What is the mean of a binomial distribution with n = 10 and p = 0.3?
A) 2
B) 3
C) 4
D) 5
B) 3
Explanation: Mean = n × p = 10 × 0.3 = 3.
Question 7
Question: What is the variance of a binomial distribution with n = 5 and p = 0.4?
A) 1.2
B) 1.5
C) 2
D) 2.5
A) 1.2
Explanation: Variance = n × p × (1-p) = 5 × 0.4 × 0.6 = 1.2.
Question 8
Question: If P(X=0) = 0.4, P(X=1) = 0.3, and P(X=2) = 0.3, is this a valid probability
distribution?
A) Yes
B) No