Public Health Dentistry – Biostatistics Multiple Choice Questions
1. Father of Health Statistics is:
A. John Snow
B. John Graunt
C. Frederick Mc Kay
D. Pierre Fauchard
2. Which of the following correlates highest correlation between variables ?
A. r= + 0.25
B. r= + 0.5
C. r= – 0.75
D. r= + 2
3. Which of the following is not a measure of central tendency ?
A. Mean
B. Mode
C. Range
D. Median
4. The arithmetical average of a number of observations is called :
A. Mean
B. Median
C. Range
D. All of the above
5. Ranking students from the individual with the highest Grade points average (GPA) to the lowest is an example of:
A. Ordinal Scale
B. Nominal Scale
C. Interval Scale
D. Ratio Scale
6. A random sample suggests that :
A. A person in a control group will not be a member of the experimental group
B. Any member of a group to be studied has an equal opportunity to be included in the study
C. Every nth name on a list is selected
D. Subjects are volunteers
7. A statistical test which indicates the chance or probability of an observed difference between two means occurring by chance is called:
A. Tests of significance
B. Means
C. Ratio
D. Normalcy
8. Best measure for central tendency in a highly skewed distribution is :
A. Median
B. Mean
C. Mode
D. Range
9. The graphic representation of frequency distribution with X and Y axis is :
A. Frequency polygon
B. Histogram
C. Pictograph
D. Pie diagram
10. A series may have all except :
A. No mode
B. One mode
C. Many modes
D. Negative mode
11. The correlation coefficient can range from :
A. 0 to +1
B. 0 to -1
C. -1 to +1
D. 0 to 100
12. As the sample size increases, standard deviation :
A. Decreases
B. Increases
C. Remains the same
D. May increase or decrease
13. In a 3*3 table, the number of degrees of freedom is:
A. 4
B. 9
C. 3
D. 81
14. Most of the values in data spread along the :
A. Mean
B. Mode
C. Median
D. Arithmetic mean
15. Prevalence of diseases is: (COMEDK-2013)
A. Rate
B. Deviation
C. Proportion
D. Ratio
16. The type II error is the acceptance of a null hypothesis as true when it is: (KAR-2003)
A. Negative valued
B. True
C. Nonexistent
D. False
17. Standard deviation is a measure of: (KAR-98, MAN-98)
A. Statistical significance
B. Central tendency
C. Variation
D. Correlation
18. Standard error of mean indicates
A. Dispersion
B. Distribution
C. Deviation
D. Variation
19. In health education program, a group of 10 people are planning to speak on a single topic of common interest. Which one of the following is best educational approach? (AIPG-06)
A. Workshop
B. Panel discussion
C. Symposium
D. Group discussion
20. For testing the statistical significance of the difference in heights of school children among three socio economic groups the most appropriate statistical test is: (AIIMS-2003)
A. One way analysis of variance (one way ANOVA)
B. Paired t-test
C. Student’s t-test
D. Chi-squared test
21. The correlation between variables A and B in a study was found to be 1.1. This indicates: (AIPG-2002)
A. Weak correlation
B. Very strong correlation
C. Moderately strong correlation
D. Computational mistake in calculating correlation
22. Which of the following is correct?
A. In negatively skewed (left skeweD. distribution curve Mean < Median
B. In Positively Skewed (right skeweD. distribution curve Mean > Median
C. In normal distribution curve, Mean = Median = Mode
D. All of the above
23. An investigator want to know the similarity of the mean peak flow of expiratory rates and non-smokers, tight smokers, moderate smokers, and heavy smokers. Which is statistical test of significance? (AIIMS MAY 2012)
A. Two way ANOVA
B. One way ANOVA
C. Chi square test
D. Student t-test
24. Sensitivity of a test is its ability to identify: (COMEDK-2003)
A. False negative
B. True positive
C. True negative
D. False positive
25. The test done for a statistically significant change in cholesterol values in a group of patients following an interventional programme is: (AIIMS-2001)
A. Unpaired “t” test
B. Paired “t” test
C. Fisher test
D. Chi square test
26. An investigator wants to study the association between maternal intake of iron supplements (Yes or No) and birth weights (in gm) of new born babies. He collects relevant data from 100 pregnant women and their newborns. What statistical test of hypothesis would you advise for the investigator in this situation? (AIIMS-2003)
A. Student t – test
B. Analysis of variance
C. Unpaired or independent t – test
D. Chi-square test
27. Square root of pq/n indicates: (AIPG-06, AIIMS-07)
A. Standard error of proportions
B. Standard error of mean
C. Standard error of difference of means
D. Standard error of difference in proportions
28. A normal distribution curve depends on
A. Range and sample size
B. Mean and sample size
C. Mean and Median
D. Mean and standard deviation
29. When variables are not measurable, which of the following is used to be represented?
A. Nominal
B. Ordinal
C. Ratio
D. Variation
30. In assessing the association between maternal nutritional status and the birth weight of newborns two investigators A and B studied separately and found significant results with P values 0.02 and 0.04 respectively. From this information what can you infer about the magnitudes of association found by the two investigators: (AIIMS-2004)
A. Nothing can be concluded as the information given is inadequate.
B. The magnitude of association found by B is more than A
C. the magnitude of association found by A is more than B
D. The estimates of association obtained by A and B will be equal, since both are significant
31. A measure of location which divides the distribution in the ratio of 3:1 is: (AIPG-2003, AIIMS-06)
A. Third Quartiles
B. Mode
C. First Quartiles
D. Median
32. More false positive on screening in a community signify that the
A. Test has low specificity
B. Disease has high prevalence
C. Disease has low prevalence
D. Test has high sensitivity
33. The most appropriate method of testing the statistical significance of the differences between means of two groups is: (AIIMS-2001)
A. Student test
B. Multiple regression analysis
C. Chi square test
D. Correlation coefficient analysis
34. Denominator while calculating the secondary attack rate includes: (AIPG-2003)
A. ALL the close contacts
B. ALL susceptible amongst close contact
C. ALL susceptible in the whole village
D. ALL the people living in next fifty houses
35. Statistics to check out mean of values is done by: (AIIMS-95)
A. Chi-square test
B. Probability test
C. Horizontal studies
D. Student’s analysis
36. When frequency is given as mild, moderate, and severe, the data scale used is:
A. Variance
B. Interval
C. Nominal
D. Ordinal
37. Which of the following is true about Chi-square test? (AIIMS-06)
A. Measures both qualitative and quantitative data
B. Measure the quantitative data between two proportion
C. Measures the qualitative data between two proportion
D. Measures qualitative data
38. Which of the following condition must be met for a valid student-t test between means of two groups? (AIIMS MAY 2012)
A. Mean should be approximately same – no
B. Number of observation must be same – no
C. Sample must be small
D. Standard deviation must be approximately same – no
39. In a study, variation in cholesterol was seen before and after giving a drug. The test which would give its significance is: (AIPG-2002)
A. Fisher’s test
B. Paired test
C. Chi square test
D. Unpaired test
40. If the mean cholesterol value of a group of normal subjects is 230 mg% with standard error of 10. The 95% confidence limits for the population
A. 220 and 240
B. 210 and 240
C. 200 and 260
D. 210 and 250
41. In a random sampling chance of being picked up is
A. Same and known
B. Not same but known
C. Same and not known
D. Not same and not known
42. The usefulness of a screening test depends upon it: (AIIMS -2003)
A. Specificity
B. Reliability
C. Sensitivity
D. Predictive value
43. Chi-square test is used to measure the degree of: (AIIMS-06)
A. Association between two variables
B. Correlation between two variables
C. Agreement between two observations
D. Causal relationships between exposure and effect
44. Accepting the null hypothesis when it is false: (COMEDK-08)
A. Type II error
B. Type IV error
C. Type III error
D. Type-I error
45. Mean weight of 100 children was 12kgs, The standard deviation was 3, Calculate the percent coefficient of variance:
A. 55%
B. 25%
C. 45%
D. 35%
46. Which statement is true about normal distribution curve?
A. Curved Skewed towards left
B. Mean -1, SD – zero
C. Curved Skewed toward right
D. SD-1, Mean – zero
47. Comparison of proportions can be made by: (C0MEDK-Q7, PGI JUNE- 13)
A. Correlation & Regression
B. Chi-square test
C. ANOVA
D. T test
48. Study that is used to compare serum cholesterol levels in obese and non-obese women and to find the relation or significant prevalence is:
A. Paired test
B. Student Y test
C. Z- test
D. Chi-square test
49. All of the following are random sampling methods except
A. Cluster sampling
B. Simple random
C. Stratified random
D. Quota sampling
50. The correlation coefficient can range from: (KAR-2003)
A. 0 to -1
B. 0 to + 1
C. 0 to 100
D. -1 to +1
51. The branch of biostatistics which deals with the births, deaths and marriage is called as: (KAR-04)
A. Vital
B. Health
C. Medical
D. Demography
52. The best sampling procedure that can be followed is: (KAR-99)
A. Stratified random
B. Systematic
C. Simple random
D. Convenient
53. Prevalence of the disease affects
A. Repeatability
B. Predictive value
C. Sensitivity
D. Specificity
54. Correlation between the height and weight of children is best represented by: (AIIMS-2001)
A. Bar diagram
B. Histogram
C. Line diagram
D. Scatter diagram
55. What is the characteristic of normal distribution? (AIPG-09)
A. Mean = Median = mode
B. Curve skewed towards the right
C. Curve skewed towards the left
D. Mean is 1, SD-zero
56. A Gaussian distribution is: (KAR-2003)
A. Poisson distribution
B. Log normal distribution
C. Variant distribution
D. Normal distribution
57. A sampling unit is defined as: (AIPG-09)
A. All of them
B. A subset of sample
C. A group of sample
D. Representing every member of sample
58. Yates correction is necessary in chi-square test when expected frequency in any one cell is: (COMEDK-08)
A. Less than 10
B. More than 10
C. Less than 5
D. More than 5
59. The number of dental caries cases reported during last 10 years are given below 250, 320, 190, 300, 5000, 100, 260, 350, 320 and 160. The epidemiologist wants to find out average number of caries cases reported in that town for last 10 yrs. The most appropriate average for this data will be: (AIIMS-2004)
A. Median
B. Mode
C. Geometric mean
D. Arithmetic mean
60. As the sample size increases standard deviation: (KAR-2003)
A. Increases
B. Decreases
C. may increase or decrease
D. Remains the same
61. When a circle is divided into different sectors corresponding to the frequencies of the variable in the distribution, the diagram is known as? (KAR-04)
A. Bar
B. Pie
C. Pictogram
D. Histogram