Bcom Bachelor of Commerce Business Statistics 1 — Questions and Answers
Question 1: Which measure of central tendency is most affected by extreme outliers?
- Mean (Correct answer)
- Median
- Mode
- Weighted average
Correct answer: Mean
The mean sums all values and divides by count, so a single extreme value can dramatically shift it, unlike the median which uses positional ranking.
Question 2: What does 'standard deviation' measure?
- The average spread of data points from the mean (Correct answer)
- The difference between the highest and lowest values
- The middle value in a dataset
- The most frequently occurring value
Correct answer: The average spread of data points from the mean
Standard deviation quantifies how much individual data points typically deviate from the mean, measuring the dispersion or variability in a dataset.
Question 3: In hypothesis testing, what is the 'null hypothesis' (H₀)?
- A statement of no effect or no difference that the test attempts to reject (Correct answer)
- The researcher's expected result
- The alternative explanation
- A hypothesis with zero probability
Correct answer: A statement of no effect or no difference that the test attempts to reject
The null hypothesis posits no relationship or effect exists; researchers gather evidence to determine whether it can be statistically rejected.
Question 4: What is a 'p-value' in statistical testing?
- The probability of observing the test result, or more extreme, assuming the null hypothesis is true (Correct answer)
- The probability that the alternative hypothesis is correct
- The confidence level of the test
- The sample size required
Correct answer: The probability of observing the test result, or more extreme, assuming the null hypothesis is true
A p-value measures how likely the observed data would occur by chance if the null hypothesis were true; a small p-value suggests the result is statistically significant.
Question 5: Which type of data can only take specific, separate values (e.g., number of customers)?
- Discrete data (Correct answer)
- Continuous data
- Nominal data
- Ordinal data
Correct answer: Discrete data
Discrete data consists of countable, distinct values with no intermediate possibilities—like the number of defective products in a batch.
Question 6: What is the 'coefficient of variation' (CV)?
- Standard deviation divided by the mean, expressed as a percentage (Correct answer)
- Variance divided by the median
- Mean divided by range
- Correlation coefficient times variance
Correct answer: Standard deviation divided by the mean, expressed as a percentage
The coefficient of variation (CV = σ/μ × 100%) provides a standardized measure of relative dispersion, enabling comparisons across datasets with different units or scales.
Bcom Bachelor of Commerce Business Statistics 1
Which measure of central tendency is most affected by extreme outliers?