In a normally distributed dataset, approximately what proportion lies within 2 standard deviations of the mean?
Show answer and explanation
Correct answer: 95%
In a normal distribution, 95% of values lie within ±2 SD of the mean.
Practice all 20 Biostatistics: Mean, Median, Risk Ratios questions
Keep practicing
More Biostatistics: Mean, Median, Risk Ratios questions
- A test’s negative predictive value increases when:
- A researcher compares the mean blood pressure of two independent groups. Which statistical test is most appropriate?
- Relative risk is most appropriately calculated in which study design?
- A dataset has the following values: 2, 3, 3, 4, 10. Which measure of central tendency is most affected by the extreme value?
- In a positively skewed distribution, which relationship between mean, median, and mode is expected?
- A study reports that smokers have a lung cancer incidence of 30 per 1,000, while nonsmokers have 5 per 1,000. What is the relative risk?