QMB 3200 Business Statistics Final
Exam | Multiple Choice & Open-Ended
Q&A | Verified Answers
Exam Structure:
Subject: Business Statistics (QMB 3200)
Source: QMB 3200 Final Exam – Verified Answers
Format: Multiple Choice & Open-Ended Q&A
1. Which Excel function can be used to compute the sample standard
deviation?
Correct Answer: STDEV.S
Rationale:
1. STDEV.S calculates standard deviation for a sample (not the entire
population).
2. It uses n-1 in the denominator (degrees of freedom correction).
3. STDEV.P is used for population standard deviation.
4. Knowing the correct Excel function is essential for accurate statistical
analysis.
2. How is the mean of a sample computed?
Correct Answer: Computed by summing all the data values and dividing
the sum by the number of items.
Rationale:
1. The sample mean (x̄ ) is the arithmetic average.
2. Formula: x̄ = (Σx) / n.
3. It is a measure of central tendency.
4. The sample mean is an unbiased estimator of the population mean μ.
3. Which symbol represents the size of a population?
Correct Answer: N
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Rationale:
1. N is the standard notation for population size.
2. Lowercase n represents sample size.
3. Distinguishing between N and n is critical for statistical formulas.
4. The finite population correction factor uses N and n.
4. Can the variance of a sample or population be negative?
Correct Answer: No. Variance cannot be negative.
Rationale:
1. Variance is the average of squared deviations from the mean.
2. Squared values are always non-negative.
3. A variance of zero means all values are identical.
4. Negative variance indicates a calculation error.
5. Which symbol represents the size of a sample?
Correct Answer: n
Rationale:
1. n is the standard notation for sample size.
2. Sample size affects standard error and margin of error.
3. Larger n increases precision and decreases standard error.
4. n is used in the denominator for sample variance (n-1).
6. Which symbol represents the standard deviation of a population?
Correct Answer: σ (sigma)
Rationale:
1. Population standard deviation is denoted by σ.
2. Sample standard deviation is denoted by s.
3. σ measures dispersion around the population mean μ.
4. σ² represents population variance.
7. Which symbol represents the variance of a population?
Correct Answer: σ²
Rationale:
1. Population variance is the square of the population standard deviation.
2. σ² = Σ(x – μ)² / N.
3. Sample variance (s²) uses n-1 in the denominator.
4. Variance is a measure of data spread.
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8. Which symbol represents the mean of a population?
Correct Answer: μ (mu)
Rationale:
1. μ is the population mean (parameter).
2. x̄ (x-bar) is the sample mean (statistic).
3. μ is a fixed but often unknown value.
4. In hypothesis testing, μ is the hypothesized value in H₀.
9. Which symbol represents the mean of a sample?
Correct Answer: x̄ (x-bar)
Rationale:
1. x̄ is the sample mean, an unbiased estimator of μ.
2. It is calculated as (Σx)/n.
3. Sampling distribution of x̄ approximates normality (CLT).
4. Used in t-tests, confidence intervals, and regression.
10. What measure of central location is most often reported for annual
income and property value data?
Correct Answer: Median
Rationale:
1. Income and property value distributions are often right-skewed
(positive skew).
2. The mean is pulled toward the tail by high-income outliers.
3. The median is resistant to outliers and better represents typical values.
4. Median is the 50th percentile; half of values are below, half above.
11. What is the range of the correlation coefficient?
Correct Answer: -1 to +1
Rationale:
1. r = +1 indicates perfect positive linear relationship.
2. r = -1 indicates perfect negative linear relationship.
3. r = 0 indicates no linear relationship.
4. Correlation does not imply causation.
12. Which Excel function can be used to compute the sample variance?
Correct Answer: VAR.S