MATH 110 Statistics Module 6 Exam | Latest
2025/2026 | Portage Learning | Verified
Questions and Answers | A+ Graded
Section 1: Introduction
This document provides the verified exam content for Module 6 of MATH 110 – Statistics
from Portage Learning, fully updated for the 2025/2026 academic year. It includes 100%
correct answers to questions covering confidence intervals, estimation, and sample size
determination. 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 confidence interval?
A) A range of values with a guaranteed true mean
B) A range of values likely to contain the population parameter
C) A fixed point estimate
D) The sample standard deviation
B) A range of values likely to contain the population parameter
Explanation: It estimates the parameter with a confidence level.
Question 2
Question: What does a 95% confidence level indicate?
A) The parameter is 95% of the sample mean
B) 95% of samples will contain the true parameter
C) The interval will be correct 95% of the time
D) 95% probability the parameter is in the interval
C) The interval will be correct 95% of the time
Explanation: Refers to long-run success rate of intervals.
Question 3
Question: For a sample mean of 50, standard error of 2, and z-score of 1.96, what is the
confidence interval (95%)?
A) (46, 54)
B) (47.08, 52.92)
C) (48, 52)
D) (45.92, 54.08)
, A) (46, 54)
Explanation: CI = 50 ± (1.96 × 2) = 50 ± 3.92 ≈ (46, 54).
Question 4
Question: What factor increases the width of a confidence interval?
A) Larger sample size
B) Smaller confidence level
C) Larger standard error
D) Lower variability
C) Larger standard error
Explanation: Wider intervals result from greater uncertainty.
Question 5
Question: What is the formula for the margin of error in a confidence interval?
A) z × standard error
B) sample mean / standard deviation
C) n × p
D) 1 - confidence level
A) z × standard error
Explanation: Margin = critical value × standard error.
Question 6
Question: If the sample size increases, what happens to the confidence interval?
A) Widens
B) Narrows
C) Stays the same
D) Becomes invalid
B) Narrows
Explanation: Larger n reduces standard error, narrowing the interval.
Question 7
Question: What is the z-score for a 99% confidence interval?
A) 1.645
B) 1.96
C) 2.33
D) 2.58
D) 2.58
Explanation: Corresponds to 99% confidence level.
Question 8
Question: For a population mean of 100, sample mean of 102, standard error of 1.5, and 95%
confidence, what is the margin of error?
A) 1.5
B) 2.94
2025/2026 | Portage Learning | Verified
Questions and Answers | A+ Graded
Section 1: Introduction
This document provides the verified exam content for Module 6 of MATH 110 – Statistics
from Portage Learning, fully updated for the 2025/2026 academic year. It includes 100%
correct answers to questions covering confidence intervals, estimation, and sample size
determination. 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 confidence interval?
A) A range of values with a guaranteed true mean
B) A range of values likely to contain the population parameter
C) A fixed point estimate
D) The sample standard deviation
B) A range of values likely to contain the population parameter
Explanation: It estimates the parameter with a confidence level.
Question 2
Question: What does a 95% confidence level indicate?
A) The parameter is 95% of the sample mean
B) 95% of samples will contain the true parameter
C) The interval will be correct 95% of the time
D) 95% probability the parameter is in the interval
C) The interval will be correct 95% of the time
Explanation: Refers to long-run success rate of intervals.
Question 3
Question: For a sample mean of 50, standard error of 2, and z-score of 1.96, what is the
confidence interval (95%)?
A) (46, 54)
B) (47.08, 52.92)
C) (48, 52)
D) (45.92, 54.08)
, A) (46, 54)
Explanation: CI = 50 ± (1.96 × 2) = 50 ± 3.92 ≈ (46, 54).
Question 4
Question: What factor increases the width of a confidence interval?
A) Larger sample size
B) Smaller confidence level
C) Larger standard error
D) Lower variability
C) Larger standard error
Explanation: Wider intervals result from greater uncertainty.
Question 5
Question: What is the formula for the margin of error in a confidence interval?
A) z × standard error
B) sample mean / standard deviation
C) n × p
D) 1 - confidence level
A) z × standard error
Explanation: Margin = critical value × standard error.
Question 6
Question: If the sample size increases, what happens to the confidence interval?
A) Widens
B) Narrows
C) Stays the same
D) Becomes invalid
B) Narrows
Explanation: Larger n reduces standard error, narrowing the interval.
Question 7
Question: What is the z-score for a 99% confidence interval?
A) 1.645
B) 1.96
C) 2.33
D) 2.58
D) 2.58
Explanation: Corresponds to 99% confidence level.
Question 8
Question: For a population mean of 100, sample mean of 102, standard error of 1.5, and 95%
confidence, what is the margin of error?
A) 1.5
B) 2.94
