StraighterLine Introduction to Statistics Exam
2025/2026 | Complete Exam with Verified
Questions & 100% Correct Answers
StraighterLine Introduction to Statistics Exam | Key Concepts: Descriptive & Inferential
Statistics, Probability, Hypothesis Testing, Correlation & Regression, Normal Distribution,
Sampling Methods, Confidence Intervals, and Data Interpretation | Expert-Verified Q&A |
Course & Exam-Ready
Introduction
This updated 2025/2026 StraighterLine Introduction to Statistics Exam resource provides fully
verified exam questions with 100% correct answers. Content covers core statistical concepts
including descriptive measures, probability rules, hypothesis testing, regression analysis,
sampling distributions, and applied data analysis. All answers are already graded A+ and ensure
complete preparation for StraighterLine Introduction to Statistics exam success.
Answer Format
All correct answers are highlighted in bold and green, with rationales that explain statistical
reasoning, reinforce problem-solving skills, and strengthen applied quantitative knowledge for
exam readiness.
Questions 1–50
1. What is the primary purpose of descriptive statistics?
a) Predict future outcomes
b) Summarize and describe data
c) Test hypotheses
d) Establish causation
b) Summarize and describe data
Rationale: Descriptive statistics involve measures like mean, median, and standard deviation to
summarize data, per descriptive statistics principles.
2. What does the standard deviation measure?
a) Central tendency of data
b) Spread of data around the mean
c) Probability of an event
d) Correlation between variables
b) Spread of data around the mean
Rationale: Standard deviation quantifies data dispersion, per descriptive statistics.
, 3. What is the probability of rolling a 3 on a six-sided die?
a) 1/3
b) 1/6
c) 1/2
d) 1/4
b) 1/6
Rationale: A fair die has 6 equally likely outcomes, so P(3) = 1/6, per probability rules.
4. What is the null hypothesis in hypothesis testing?
a) The hypothesis that there is an effect
b) The hypothesis that there is no effect
c) The hypothesis that data is normally distributed
d) The hypothesis that samples are biased
b) The hypothesis that there is no effect
Rationale: The null hypothesis (H₀) assumes no difference or effect, per hypothesis testing
principles.
5. What does a correlation coefficient of -0.8 indicate?
a) No relationship
b) Strong positive relationship
c) Strong negative relationship
d) Weak negative relationship
c) Strong negative relationship
Rationale: A correlation coefficient near -1 indicates a strong negative linear relationship, per
correlation analysis.
6. In a normal distribution, what percentage of data lies within one
standard deviation of the mean?
a) 50%
b) 68%
c) 95%
d) 99.7%
b) 68%
Rationale: The empirical rule states that 68% of data falls within one standard deviation in a
normal distribution, per normal distribution principles.
7. What is a simple random sample?
a) A sample where every unit has an equal chance of selection
b) A sample divided into groups
c) A sample selected based on convenience
d) A sample with unequal probabilities
a) A sample where every unit has an equal chance of selection
Rationale: Simple random sampling ensures unbiased selection, per sampling methods.
8. What is a 95% confidence interval?
a) A range where the sample mean always lies
2025/2026 | Complete Exam with Verified
Questions & 100% Correct Answers
StraighterLine Introduction to Statistics Exam | Key Concepts: Descriptive & Inferential
Statistics, Probability, Hypothesis Testing, Correlation & Regression, Normal Distribution,
Sampling Methods, Confidence Intervals, and Data Interpretation | Expert-Verified Q&A |
Course & Exam-Ready
Introduction
This updated 2025/2026 StraighterLine Introduction to Statistics Exam resource provides fully
verified exam questions with 100% correct answers. Content covers core statistical concepts
including descriptive measures, probability rules, hypothesis testing, regression analysis,
sampling distributions, and applied data analysis. All answers are already graded A+ and ensure
complete preparation for StraighterLine Introduction to Statistics exam success.
Answer Format
All correct answers are highlighted in bold and green, with rationales that explain statistical
reasoning, reinforce problem-solving skills, and strengthen applied quantitative knowledge for
exam readiness.
Questions 1–50
1. What is the primary purpose of descriptive statistics?
a) Predict future outcomes
b) Summarize and describe data
c) Test hypotheses
d) Establish causation
b) Summarize and describe data
Rationale: Descriptive statistics involve measures like mean, median, and standard deviation to
summarize data, per descriptive statistics principles.
2. What does the standard deviation measure?
a) Central tendency of data
b) Spread of data around the mean
c) Probability of an event
d) Correlation between variables
b) Spread of data around the mean
Rationale: Standard deviation quantifies data dispersion, per descriptive statistics.
, 3. What is the probability of rolling a 3 on a six-sided die?
a) 1/3
b) 1/6
c) 1/2
d) 1/4
b) 1/6
Rationale: A fair die has 6 equally likely outcomes, so P(3) = 1/6, per probability rules.
4. What is the null hypothesis in hypothesis testing?
a) The hypothesis that there is an effect
b) The hypothesis that there is no effect
c) The hypothesis that data is normally distributed
d) The hypothesis that samples are biased
b) The hypothesis that there is no effect
Rationale: The null hypothesis (H₀) assumes no difference or effect, per hypothesis testing
principles.
5. What does a correlation coefficient of -0.8 indicate?
a) No relationship
b) Strong positive relationship
c) Strong negative relationship
d) Weak negative relationship
c) Strong negative relationship
Rationale: A correlation coefficient near -1 indicates a strong negative linear relationship, per
correlation analysis.
6. In a normal distribution, what percentage of data lies within one
standard deviation of the mean?
a) 50%
b) 68%
c) 95%
d) 99.7%
b) 68%
Rationale: The empirical rule states that 68% of data falls within one standard deviation in a
normal distribution, per normal distribution principles.
7. What is a simple random sample?
a) A sample where every unit has an equal chance of selection
b) A sample divided into groups
c) A sample selected based on convenience
d) A sample with unequal probabilities
a) A sample where every unit has an equal chance of selection
Rationale: Simple random sampling ensures unbiased selection, per sampling methods.
8. What is a 95% confidence interval?
a) A range where the sample mean always lies
