lecture 4 mcqs part 2

Question 1

. A study compares fasting blood glucose levels (continuous, normally distributed) between two independent groups. What test should be used?
A) Paired t-test
B) Independent (unpaired) t-test
C) Chi-square test
D) Wilcoxon signed-rank test

Answer 1

B

Question 2

2. You want to compare pain scores (on a 0–10 scale) before and after treatment in the same group of patients. Data is skewed. Which test is best?
   A) Wilcoxon signed-rank test
   B) Paired t-test
   C) Independent t-test
   D) Kruskal-Wallis test

Answer 2

A

Question 3

3. A researcher compares systolic blood pressure across three unrelated diet groups, with normal distribution. What test should be used?
   A) One-way ANOVA
   B) Paired t-test
   C) Wilcoxon rank-sum test
   D) McNemar’s test

Answer 3

A

Question 4

4. You assess if a new brushing technique improves plaque scores in the same patients, measured before and after training. What test applies?
   A) Chi-square test
   B) Independent t-test
   C) Paired t-test
   D) ANOVA

Answer 4

C

Question 5

5. What is the non-parametric equivalent of the independent t-test?
   A) Kruskal-Wallis test
   B) Chi-square test
   C) Wilcoxon rank-sum (Mann-Whitney U) test
   D) Fisher’s exact test

Answer 5

c

Question 6

6. A dentist compares types of toothpaste (3 brands) for whitening effect. Outcome = binary (whitened: yes/no). Which test?
   A) One-way ANOVA
   B) Chi-square test
   C) McNemar’s test
   D) Kruskal-Wallis test

Answer 6

b

Question 7

7. Which test is used to assess if two categorical variables (e.g., gender and brushing frequency category) are associated?
   A) ANOVA
   B) Chi-square test
   C) Paired t-test
   D) Wilcoxon rank-sum test

Answer 7

b

Question 8

8. A study examines plaque index in three related groups measured at three different time points (baseline, 1 month, 3 months). Data is continuous and normal. Which test applies?
   A) One-way ANOVA
   B) Repeated-measures ANOVA
   C) Kruskal-Wallis test
   D) Chi-square test

Answer 8

B

Question 9

9. Which of the following would violate the assumptions of a paired t-test?
   A) Differences are normally distributed
   B) Observations are from the same subjects
   C) Groups are independent
   D) Outcome is continuous

Answer 9

C

Question 10

10. In a crossover trial, patients use two treatments (A and B) on opposite sides of the mouth. The outcome is binary (pain: yes/no). Which test is best?
    A) McNemar’s test
    B) Paired t-test
    C) Chi-square test
    D) Fisher’s exact test

Answer 10

A

Question 11

11. Which test compares medians between two independent, non-normally distributed groups?
    A) Paired t-test
    B) ANOVA
    C) Wilcoxon rank-sum test
    D) McNemar’s test

Answer 11

C

Question 12

12. A study compares brushing frequency across three income categories. Brushing is measured as a continuous, non-normal variable. What’s the best test?
    A) One-way ANOVA
    B) Kruskal-Wallis test
    C) Independent t-test
    D) Chi-square test

Answer 12

B

Question 13

13. What test is appropriate to compare proportions in two small groups (e.g., 5/10 vs. 2/10)?
    A) Paired t-test
    B) Chi-square test
    C) Fisher’s exact test
    D) McNemar’s test

Answer 13

C

Question 14

14. A researcher wants to test if average plaque index differs between right and left molars in the same patient. Data is normal. Which test?
    A) Independent t-test
    B) One-way ANOVA
    C) Wilcoxon rank-sum
    D) Paired t-test

Answer 14

D

Question 15

15. A significant ANOVA result tells you:
    A) All groups are significantly different from each other
    B) At least one group mean differs
    C) The smallest group is different
    D) Medians are significantly different

Answer 15

B

Question 16

16. After a significant ANOVA result, what test is commonly used for pairwise comparisons?
    A) Kruskal-Wallis
    B) Post-hoc test (e.g., Bonferroni)
    C) Chi-square
    D) Fisher’s exact test

Answer 16

B

Question 17

17. A dental school examines if flossing status (yes/no) differs by age group (young, middle-aged, older). Which test applies?
    A) ANOVA
    B) Fisher’s exact
    C) McNemar’s
    D) Chi-square test

Answer 17

d

Question 18

18. Which test is used for ordinal data in two independent groups?
    A) Wilcoxon rank-sum test
    B) Paired t-test
    C) McNemar’s test
    D) Repeated-measures ANOVA

Answer 18

A

Question 19

19. When would you use McNemar’s test instead of chi-square?
    A) Comparing unrelated groups
    B) Repeated measurements on the same subject with binary outcome
    C) Continuous data with small sample
    D) When comparing proportions from multiple groups

Answer 19

B

Question 20

20. Which test best compares mean number of decayed teeth in two unrelated groups (normal data)?
    A) Wilcoxon signed-rank test
    B) Paired t-test
    C) Independent t-test
    D) Kruskal-Wallis test

Answer 20

C

Question 21

21. A study compares resting heart rate between three groups: runners, swimmers, and non-athletes. The data is continuous and normally distributed. What is the correct test?
    A) Wilcoxon rank-sum test
    B) Chi-square test
    C) One-way ANOVA
    D) Paired t-test

Answer 21

C

Question 22

22. When would it be inappropriate to use a paired t-test?
    A) Comparing before-and-after treatment scores in the same group
    B) Comparing two sides of the mouth in the same patient
    C) Comparing treatment outcomes in unrelated participants
    D) Comparing follow-up scores in matched pairs

Answer 22

C

Question 23

23. What test is used when comparing two related samples with a non-normal distribution?
    A) McNemar’s test
    B) Wilcoxon signed-rank test
    C) Paired t-test
    D) Fisher’s exact test

Answer 23

B

Question 24

24. A study compares the percentage of patients who use mouthwash in two independent dental clinics. Sample sizes are small. Which test is best?
    A) Chi-square test
    B) McNemar’s test
    C) Paired t-test
    D) Fisher’s exact test

Answer 24

D

Question 25

25. Which of the following tests is used for three or more independent groups when the outcome is non-normal? A) One-way ANOVA B) Kruskal-Wallis test C) Repeated-measures ANOVA D) Paired t-test

Answer 25

B

Question 26

26. What is the correct test for a binary outcome compared across two independent groups with large sample sizes? A) Paired t-test B) McNemar’s test C) Chi-square test D) Kruskal-Wallis test

Answer 26

C

Question 27

27. Which test compares proportions in matched pairs (e.g., pre-post or left vs. right)? A) Chi-square B) McNemar’s test C) One-way ANOVA D) Wilcoxon rank-sum

Answer 27

B

Question 28

28. A study compares pain levels (0–10 scale, not normally distributed) between two unrelated groups. What test is best? A) Wilcoxon rank-sum test B) Independent t-test C) Paired t-test D) Fisher’s exact test

Answer 28

A

Question 29

29. A crossover trial compares two mouth rinses used on different days by the same subjects. The outcome is continuous, normal. Which test applies? A) Chi-square B) Independent t-test C) Paired t-test D) McNemar’s test

Answer 29

C

Question 30

30. A researcher compares brushing frequency (categorical) between males and females. Which test applies? A) Fisher’s exact test B) Kruskal-Wallis test C) Chi-square test D) Paired t-test

Answer 30

C

Question 31

31. What is a key assumption of an independent t-test? A) Repeated measurements in the same subjects B) Normal distribution of outcome in both groups C) Binary outcome D) Paired data

Answer 31

B

Question 32

32. Which test compares more than two paired groups? A) One-way ANOVA B) McNemar’s test C) Repeated-measures ANOVA D) Kruskal-Wallis test

Answer 32

C

Question 33

33. When would you use a Wilcoxon rank-sum test instead of a t-test? A) When the data is categorical B) When the sample size is large C) When data is skewed or not normally distributed D) When variables are binary

Answer 33

C

Question 34

34. A study compares blood pressure changes from baseline to follow-up in the same patients. Data is normal. Which test applies? A) Independent t-test B) Paired t-test C) Kruskal-Wallis test D) Chi-square test

Answer 34

B

Question 35

35. Which of the following is a non-parametric alternative to the repeated-measures ANOVA? A) Kruskal-Wallis test B) Wilcoxon signed-rank test C) Friedman test D) McNemar’s test

Answer 35

C

Question 36

36. What test is best for comparing binary outcomes (e.g., bleeding yes/no) in two unmatched groups with large sample sizes? A) Paired t-test B) McNemar’s test C) Chi-square test D) Wilcoxon rank-sum

Answer 36

C

Question 37

37. A test is used to compare satisfaction scores (1–10 Likert scale, skewed) among three independent groups. What’s most appropriate? A) One-way ANOVA B) Paired t-test C) Kruskal-Wallis test D) Chi-square test

Answer 37

C

Question 38

38. A dentist measures gum bleeding before and after treatment in the same group. Data is not normally distributed. Which test should be used? A) Independent t-test B) Kruskal-Wallis test C) Wilcoxon signed-rank test D) Chi-square test

Answer 38

C

Question 39

39. A survey finds that 80% of participants floss regularly in Clinic A vs. 60% in Clinic B. Both clinics have large samples. Best test? A) Chi-square test B) McNemar’s test C) Paired t-test D) Kruskal-Wallis

Answer 39

A

Question 40

40. Which test is most suitable for comparing the mean number of fillings across four unrelated groups, assuming normality? A) Chi-square B) Fisher’s exact test C) One-way ANOVA D) Wilcoxon rank-sum

Answer 40

C