Biostatistics MCQs

1. : Biostatistics is mainly concerned with:
(A) Study of diseases only
(B) Application of statistical methods to biological and health sciences
(C) Study of physics in medicine
(D) Study of chemistry of life

2. : In statistics, a population refers to:
(A) A group of humans only
(B) A sample of individuals
(C) The entire set of individuals or observations of interest
(D) Only animals in a study

3. : A subset of the population selected for study is called:
(A) Variable
(B) Parameter
(C) Sample
(D) Statistic

4. : Mean, median, and mode are examples of:
(A) Measures of variability
(B) Measures of central tendency
(C) Hypothesis testing methods
(D) Probability distributions

5. : Standard deviation is a measure of:
(A) Central tendency
(B) Correlation
(C) Dispersion or spread of data
(D) Sample size

6. : The most frequently occurring value in a dataset is called:
(A) Mean
(B) Median
(C) Mode
(D) Variance

7. : If the mean = median = mode, the distribution is:
(A) Skewed
(B) Normal
(C) Bimodal
(D) Uniform

8. : In hypothesis testing, the null hypothesis (H₀) usually states:
(A) There is no significant difference
(B) There is always a difference
(C) The sample is biased
(D) The test is invalid

9. : Type I error occurs when:
(A) A true null hypothesis is rejected
(B) A false null hypothesis is rejected
(C) A false null hypothesis is accepted
(D) The sample size is too small

10. : Type II error occurs when:
(A) A false null hypothesis is accepted
(B) A true null hypothesis is accepted
(C) A true null hypothesis is rejected
(D) The test statistic is too large

11. : The p-value in hypothesis testing represents:
(A) The probability that null hypothesis is true
(B) The probability of observing the result assuming null hypothesis is true
(C) The sample size
(D) The standard deviation

12. : A p-value less than 0.05 usually indicates:
(A) Strong evidence against the null hypothesis
(B) Null hypothesis is always true
(C) No evidence against the null hypothesis
(D) Large sample bias

13. : Which statistical test is used to compare means of two groups?
(A) Chi-square test
(B) T-test
(C) ANOVA
(D) Regression analysis

14. : ANOVA is used to:
(A) Compare variance of two samples
(B) Compare means of more than two groups
(C) Test correlation between two variables
(D) Estimate population proportion

15. : The correlation coefficient (r) ranges between:
(A) –10 to +10
(B) –5 to +5
(C) –1 to +1
(D) 0 to +1

16. : A correlation coefficient (r = 0) means:
(A) Strong relationship
(B) No relationship
(C) Perfect positive correlation
(D) Perfect negative correlation

17. : A scatter plot is mainly used to show:
(A) Central tendency
(B) Relationship between two variables
(C) Frequency distribution
(D) Hypothesis testing

18. : The chi-square test is used for:
(A) Comparing means
(B) Testing association between categorical variables
(C) Measuring dispersion
(D) Estimating variance

19. : Regression analysis is used to:
(A) Compare two groups
(B) Predict one variable based on another
(C) Test randomness of sample
(D) Measure standard deviation

20. : Which graph is best suited to show frequency distribution of data?
(A) Line graph
(B) Histogram
(C) Scatter plot
(D) Pie chart

21. : In biostatistics, prevalence refers to:
(A) Number of new cases in a population
(B) Number of existing cases in a population at a given time
(C) Mortality rate
(D) Risk factor analysis

22. : Incidence rate measures:
(A) Number of deaths in a population
(B) Number of new cases in a given period
(C) Total population size
(D) Exposure to risk factors

23. : Which sampling method gives every individual an equal chance of being selected?
(A) Stratified sampling
(B) Random sampling
(C) Cluster sampling
(D) Convenience sampling

24. : The standard error of the mean decreases when:
(A) Sample size increases
(B) Sample size decreases
(C) Variance increases
(D) Data are skewed

25. : The 95% confidence interval means:
(A) 95% of population values are correct
(B) There is 95% chance the true population parameter lies within the interval
(C) 95% of the data is error-free
(D) The null hypothesis is true 95% of the time