BIOSTATISTICS MCQs with Key
1. A study was conducted in America to find out the proportion of blacks and white Americans in California. This variable chosen is:
a. Nominal
b. Ordinal
c. Continuous
d. Discreet numerical
e. Dichotomous
Key: True: e
2. The median of the following data, is: 1,2,4,6,8,10,11,13
a. 6
b. 8
c. 7
d. 10
e. 9
Key: True: c
3. A household survey of 10 families was conducted by students of 4th year MBBS. In the collected data, the ages of heads of families were: 32, 34, 35, 36, 36, 42, 44, 46, 48, and 52. The mean age of heads of families is
a. 36
b. 38.5
c. 40
d. 40.5
e. 42
Key: True: d
4. A nutritional research team followed serum levels of vitamin B12 in 120 children for three years to determine the association between cyanocobalamin deficiency and the subsequent risk of developing Megaloblastic anemia. The results were as follows:
VITAMIN B12 LEVELS
Mean 260 pg/mL
Median 226 pg/mL
Mode 194 pg/mL
From the data, it can be concluded that this distribution is:
a. Normal
b. Negatively
c. Positively skewed
d. Bimodal
e. Multimodal
Key: True: c
5. Serum cholesterol levels for two groups of Americans were recorded in 1989. The mean cholesterol levels of the two groups were compared. To determine whether the measurements were significantly different or not, the most appropriate statistical test would be:
a. Chi-square test
b. Correlation analysis
c. F test (ANOVA)
d. Student’s t test
e. Regression analysis
Key: True: d
6. In a descriptive study the mean is 220 and the standard error is 10, the 95 confidence limits would be:
a. 210 to 230
b. 215 to 225
c. 200 to 240
d. 220 to 230
e. 205 to 235
Key: True: c
7. For a survey, a village is divided into 5 lanes, each lane is sampled randomly. It is an example of:
a. Simple random sampling
b. Standard random sampling
c. Systematic random sampling
d. Cluster random sampling
e. Quasi random sampling
Key: True: d
8. The birth weights in a hospital are to be presented in a graph. This is best done by a:
a. Bar diagram
b. Pie chart
c. Histogram
d. Pictogram
e. Frequency chart
Key: True: c
9. An analysis of the race of patients who visit an emergency room reveals that 40% are white, 25% are black, 20% are Native American, and 15% are Asian. These data would best be depicted graphically with a
a. Venn diagram
b. Cumulative frequency graph
c. Normal curve
d. Histogram
e. Pie chart
Key: True: e
10. If six families were surveyed and the numbers of children per family were found to be 2, 3, 4, 4, 5, 6, fine the mean number of children per family
a. 2
b. 3.5
c. 4
d. 6
e. 4.5
Key: True: c
11. If, in one of the groups of premature infants, the maximum value for hexosaminidase A was substituted with a much higher value. The value which is unlikely to be affected by this higher value is:
aVariance
a. Range
a. Standard deviation
b. Median
c. Mean
Key: True: d
12. A nutritional research team followed serum levels of vitamin B12 and folic acid in
125 children for five years to determine the association between cyanocobalamin
deficiency and the subsequent risk of developing megaloblastic anemia. The results were as follows:
VITAMIN B12 LEVELS
Mean 262 pg/mL
Median 228 pg/mL
Mode 196 pg/mL
From the data, it can be concluded that this distribution is
a. Normal
b. Positively skewed
c. Negatively skewed
d. Skewed toward the left
e. Unable to be identified
Key: True: b
14. In study carried out in the hospital ward, every 10th admitted patient was included in the sample, which sampling procedure is this:
a. Random sampling
b. Stratified sampling
c. Quota sampling
d. Convenient sampling
e. Systematic sampling
Key: True: e
15. Three groups of subjects were followed over the course of five years to compare
treatments for sideroblastic anemia. The most appropriate statistical analysis to determine the quantitative serologic differences resulting from these treatments would be a(n)
a. Regression analysis
b. F test (ANOVA)
c. Correlation analysis
d. Chi-square test
e. T test
Key: True: b
16. In a class of 134 medical students, the mean systolic blood pressure was found to be 126 mm Hg with a standard deviation of 6 mm Hg If the blood pressures in this sample are normally distributed, what portion of the medical students will have systolic blood pressures above 132 mm Hg?
a. 0.5%
b. 2.5%
c. 5%
d. 16%
e. 32%
Key: True: d
18. In a household survey conducted on ten families the frequency of family members in different age groups was less than 5 years 21, 5 – 14 years 16, 15 – 64 years 77 &> 65 years 1. The relative frequency of members in 15 – 64 years age group would be:
a. 60.5%
b. 67.5%
c. 70.5%
d. 76.5%
e. 80.5%
Key: True: b
19. Malaria cases were reported throughout the world during the year 1971 – 1978 excluding African region. These cases can be best represented by:
a. Frequency polygon
b. Histogram
c. Line diagram
d. Pictogram
e. Scatter diagram
Key: True: c
20. There are 50 individual in population and they have same hemoglobin level that is 14g/dL. As there is no variability, the standard deviation will be:
a. 0
b. 1, -1
c. 0, 1
d. +2
e. -2
Key: True: a
21. A mean hemoglobin level of 100 women in a population sample is 12g/dL with standard deviation of 2. The confidence interval for the population mean would be:
a. 10.4 – 11.6
b. 11.6 – 12.4
c. 12.4 – 13.6
d. 13.6 – 14.4
e. 14.4 – 15.6
Key: True: b
22. The students of4th year MBBS class visited a school. The numbers of students per class from class I to class IX were as follows:
27, 23, 15, 18, 30, 24, 8, 12 and 16. The median number in this series is:
a. 12
b. 15
c. 16
d. 18
e. 23
Key: True: d
23. In a village of 300 population, 60% constitute Hindus, 20% Muslims, 10% Sikhs and 10% Christians. We want to take a sample of 10% of the population to study the eating habits of this population. The best method would be:
a. Simple random sampling
b. Stratified random sampling
c. Systematic random sampling
d. Non-random sampling
e. Cluster sampling
Key: True: b
24. The median of a series of 20 observations is 10, mean is 11.5 and mode is 11, which of the following measures can be subjected to statistical manipulation:
a. Sample size
b. Mean
c. Median
d. Mode
e. Range
Key: True: b
25. Which of the following can have more than one value?
a. The mean
b. The range
c. The mode
d. The median
e. Standard deviation.
Key: True: c
26. The distribution of heights of the girls was plotted. The most frequent value was 5’ – 2”, which gives a single most important clue to its:
a. Negative skewness
b. Positive skewness
c. Normal distribution
d. Large standard deviation
e. Multi modal distribution
Key: True: c
27. A large study of bladder cancer and cigarette smoking produced the following data:
INCIDENCE OF BLADDER CANCER (per 100,000 males per year)
Cigarette smokers 48.0
Non-smokers 25.4
The relative risk of developing bladder cancers compared with non-smokers is:
a. Categorical variable
b. Ordinal data
c. Numerical, continuous variable
d. Numerical, discrete variable
e. Proportion
Key: True: c
28. Birth rates of a population of infants at 40 weeks gestational age are approximately normally distributed, with a mean of 3000 grams. Roughly 68% of such infants weigh between 2500 and 3500 at birth. If a sample of 100 infants was studied, the standard error would be
a. 50
b. 100
c. 200
d. 250
e. 500
Key: True: a
29. When the standard for accepting the difference was at P-value of 0.05 and the calculated value was 0.01, the null hypothesis was rejected by the researcher. What do you think of results?
a. Wrongly rejected
b. Significant difference
c. No difference
d. Alternate hypothesis is wrong
e. Sample size was small
Key: True: b
30. A study was conducted to assess the heights of 30 students . By chance all of the students were found to be of the same height. The standard deviation of this study sample is:
a. Zero
b. 0 −− -1
c. 0 −− +1
d. 0 −− +2
e. 0 −− -2
Key: True: a
31. In the Medical OPD of teaching hospital. diastolic blood pressures of 10 patients were as follows:
80, 75, 81, 79, 71, 95, 75, 77, 84, & 90. The mean of this data is:
a. 80
b. 81
c. 82
d. 83
e. 84
Key: True: b
32. A normal distribution curve is based mainly on:
a. Mean and sample size
b. Mean and standard deviation
c. Range and sample size
d. Range and standard deviation
e. Mean and range
Key: True: b
146. The relative frequency of a class is obtained by:
a. Dividing the frequency of that class by the sum of all frequencies
b. Multiplying the frequency of that class by 100
c. Dividing the frequency of that class by 100
d. Dividing the sum of frequencies by 100
e. Dividing the frequency of that class by the sum of all frequencies and multiplied by 100
Key: True: e
33. A study was conducted to assess the height of students of 4th year in 10 Medical colleges the values of heights ranged between 5.5 – 5.10 feet. A histogram has been selected by the researcher to present these results as it is a:
a. Nominal data
b. Categorical data
c. Both qualitative and quantitative data
d. Continuous data
e. Discrete numerical data
Key: True: d
34. A study was conducted to assess the height of students of 4th year in 10 Medical colleges. The values of heights ranged between 5.5 – 5.10 feet. Which graph should be used by the researcher to present the obtained data?
a. Bar chart
b. Histogram
c. Pie chart
d. Scatter diagram
e. Line graph
Key: True: b
35. The median of the following data, is: 1,2,4,6,8,10,11,13
a. 6
b. 8
c. 7
d. 10
e. 9
Key: True: c
36. A large study of bladder cancer and cigarette smoking produced the following data:
INCIDENCE OF BLADDER CANCER (per 100,000 males per year)
Cigarette smokers 48.0
Non-smokers 25.4
The relative risk of developing bladder cancers compared with non-smokers is:
a. Categorical variable
b. Ordinal data
c. Numerical, continuous variable
d. Numerical, discrete variable
e. None of the above
Key: True: c
37. Formula for chi square value is:
a. O- E
E
b. O – E
E2
c. (O – E)2
N
d. Σ(O – E)2
E
e. (O – E)2
E
Key:
38. The median of the following data, is:
1, 2, 4, 6, 8, 10, 11, 13
a. 6
b. 8
c. 7
d. 10
e. 5
Key: True: c
39. After arranging the data is ascending or descending order of magnitude, the value of middle observation:
a. Mean
b. Mode
c. Median
d. Geometric mean
e. Mean deviation
Key: True: c
40. The area between two standard deviations on either side of the mean (X + 2S.D) will include approx how much values in the distribution?
a. 68%
b. 95%
c. 99.7%
d. 100%
e. 90%
Key: True: b
41. Following test of significance will be used when more than two groups are to be compared?
a. “t” test
b. Chi-square test
c. Z-test
d. Standard error of proportion
e. Standard error of mean
Key: True: b
42. If the mean cholesterol value of a group of normal subjects is 230 mg% with a standard error of 20. The 95% confidence limit for the population is:
a. 220-240
b. 210-250
c. 200-260
d. 190-270
e. 180-280
Key: True: d
43. Birth rates of a population of infants at 36 weeks gestational age are approximately normally distributed, with a mean of 2500 grams. Roughly 95% of such infants weigh between 1900 and 3100 grams at birth. If a sample of 225 infants was studied the standard error would be:
a. 10
b. 20
c. 30
d. 40
e. 50
Key: True: b
44. In a Medical College there are 86 students in final year, 102 in fourth year, 106 in Third year, 104 in second year and 100 in first year. The relative frequency of fourth year students would be:
a. 5.5%
b. 10.5%
c. 15.5%
d. 20.5%
e. 25.5%
Key: True: d
45. The distribution of height of the girls in a University was plotted. The most frequent value was five feet and two inches, while mean height was five feet and eight inches. This show:
a. Negative skewness
b. Positive skewness
c. Normal distribution
d. Large standard deviation
e. Multimodal distribution
Key: True: b
46. A household survey of 10 families was conducted by students of 4th year MBBS. In the data they collected, the ages of heads of families were: 32,32,36,48,34,46,35,44,36 and 32 years. The mode in this series:
a. 32
b. 34
c. 36
d. 44
e. 46
Key: True: a
47. In the Medical OPD of teaching hospital, diastolic blood pressures of 10 patients were as follows:
80, 75, 81, 79, 71, 95, 75, 77, 84, & 90. The mean of this data is:
a. 80
b. 81
c. 82
d. 83
e. 84
Key: True: b
48. An investigator gets a positively skewed data on account of having only a small number of simple numerical observations at extremely high values. It will give an over estimate of:
a. Mean
b. Median
c. Mode
d. Correlation
e. Modal class
Key: True: a
49. An investigator gets a positively skewed data on account of having only a small number of simple numerical observations at extremely high values. Which measure of central tendency should he select if data is numerical?
a. Mean
b. Median
c. Mode
d. Geometric mean
e. Modal class
Key: True: b
50. When a relationship between the heart rate and valsalva’s ratio is studied, mean is useful but dispersion of the data is also very useful. Which method of spread will be more useful in this?
a. Range
b. Standard deviation
c. Coefficient of variance
d. Percentage
e. Inter quatile range
Key: True: c
58. In a descriptive study the mean is 200 and the standard error is 5, the 95 confidence limits would be:
f. 180 to 200
g. 190 to 200
h. 180 to 210
i. 200 to 220
j. 190 to 210
Key: e
59. An analysis of the race of patients who visit an emergency room reveals that 40% are white, 25% are black, 20% are Native American, and 15% are Asian. These data would best be depicted graphically with a
f. Venn diagram
g. Cumulative frequency graph
h. Normal curve
i. Histogram
j. Pie chart
Key: True: e
60. An investigator gets a positively skewed data on account of having only a small number of simple numerical observations at extremely high values. It will give an over estimate of:
a. Mean
b. Median
c. Mode
d. Correlation
e. Modal class
Key a
61. In a household survey conducted on ten families the frequency of family members in different age groups was less than 5 years 21, 5 – 14 years 16, 15 – 64 years 77 &> 65 years 1. The relative frequency of members in 15 – 64 years age group would be:
f. 47%
g. 57%
h. 67%
i. 77%
j. 87%
Key: b
Q15. At endocrinology unit, serum calcium levels of 200 patients of hyperparathyroidism were checked. The mean serum calcium level was 14mg/dl with a variance of 0.5. The 95%confidence interval would be:
a) 13.2-15.2
b) 13.5-14.5
c) 13.5-15.5
d) 13.7-14.3
e) 13.9-14.1
Key: e
Q1. While entering the data into SPSS, the analyst assigned numbers from 1-5 to different skin colors; cyanotic-1, reddish-2, pallor-3, bluish purple-4, yellowish-5. This type of variable will be categorized as:
a) Nominal
b) Ordinal
c) Dichotomous
d) Continuous
e) Discrete
Q2. The cardiologist expresses the amount of edema in CCF patients in terms of absent, mild, moderate and severe. The statistician will describe this data as:
a) Nominal
b) Ordinal
c) Dichotomous
d) Continuous
e) Discrete
Q3. Marks obtained by batch A of 4th year students in Community Medicine viva were as follows:
70, 68, 65, 60, 55, 55, 54, 52, 50, 50.
The mean value of given data is:
a) 55.9
b) 56.9
c) 57.9
d) 58.9
e) 59.9
Q4. While preparing the report of gastroenteritis outbreak investigation the researcher wanted to present the data i.e. no of cases related to time, graphically. Which graph would you suggest?
a) Bar chart
b) Pictogram
c) Pie chart
d) Histogram
e) Scatter diagram
Q5. During a research on dental caries the level of fluoride was checked in different region of Punjab. The measures of central tendency, for the data obtained, were as follows:
Mean 0.5mg/L
Median 0.7mg/L
Mode 1.0mg/L
If you present this data graphically it will be:
a) Normally distributed
b) Negatively skewed
c) Positively skewed
d) Bimodal
e) Polymodal
Q6. In a group of 200 patients suspected of suffering from renal failure, were tested for their blood urea levels. The mean blood urea level was 75mg/dl with a standard deviation of 5mg/dl. If these levels are normally distributed, what proportion of renal patients will have blood urea level less than 70 mg/dl?
a) 68%
b) 34%
c) 16%
d) 13.5%
e) 2.5%
Q7. A random sample of 256 students was selected from primary school to find out the nutritional status of the community by calculating BMI. The mean BMI was 22.5 and standard deviation was 2.5, the standard error of this sample mean will be:
a) 0.05
b) 0.15
c) 0.25
d) 0.35
e) 0.45
Q8. 4th year students studied the role of edema feet in impairing women’s ability to walk around in last trimester of pregnancy. The results were compared between grade I, II & III edema. The most appropriate statistical test to compare the results would be:
a) SE of difference between two means
b) chi-square test
c) SE of mean
d) ANOVA
e) SE of proportion
Q9. Cumulative frequency curve showing masses of 50 boys.
The approximate median of the data presented is:
a) 70 kg
b) 74kg
c) 75kg
d) 79kg
e) 80kg
Q10. A certain firm recuits drivers, office workers and mechanics. The firm selected members from each group to represent themselves in the workers committee. This type of sampling will be classified as:
a) Simple random
b) Systematic
c) Stratified
d) Quota
e) Cluster
Q11. Weights in kg of 10 pregnant ladies, were recorded in antenatal clinic. The mean weight was 78kg and the variance was 45kg. The standard deviation of the sample would be:
a) 6.7
b) 6.8
c) 6.9
d) 7.0
e) 7.1
Q12. Six volunteers took a cholesterol lowering diet for 3 months and mean cholesterol levels were measured before and after the trial diet. The appropriate test of statistical significance for this trial will be:
a) Chi-square test
b) Odd’s ratio
c) Paired t- test
d) unpaired t-test
e) Z test
Q13. 100 diabetic patients underwent a trial for dietary management to reduce their blood sugar levels. Analysis showed insignificant results. Which error should be ruled out in the given situation to accept the null hypothesis:
a) beta error
b) alpha error
c) Measurement error
d) Random error
e) Sampling error
Q14.Suppose you are a research officer and given two data sets to decide which set has more dispersion. The measure you will choose to take your decision accurately is:
a) Range
b) Mean deviation
c) Variance
d) Standard deviation
e) Coefficient of variance
Q15. A survey was done on 500 FSc students of 3 different colleges to see their career choices in future. 120 opted for engineering, 150 for medicine, 130 for MBA, 40 for masters in IT, 25 for arts and crafts and 35 for Armed forces. The relative frequency of students who voted for MBA would be:
a) 8%
b) 24%
c) 26%
d) 30%
e) 50%
1) Serum ALT levels of Hepatitis c positive patients taking interferon therapy were done repeatedly as a marker to see the effect of therapy. This variable chosen is:
a) Nominal
b) Ordinal
c) Discrete
d) Continuous
e) Dichotomous
Key: d
2) chairman POF board has announced scholarships for the students of WMC achieving 1st,2nd and 3rd positions in UHS in their relevant professional exams. The data of position holder students is categorized as
a) Nominal
b) Ordinal
c) Discrete
d) Continuous
e) Dichotomous
Key: b
3) A survey was conducted to see the %age of utilization of family plaining services by male and female persons among married couples. The of this variable is
a) Nominal
b) Ordinal
c) Discrete
d) Continuous
e) Dichotomous
Key: e
4) While monitoring the growth of children of 15 years in OPD. He children are divided into 3classes of ages 1-5years,6-10 and 11-15years.the class interval between these three classes of children is
a) 0
b) 2
c) 3
d) 4
e) 5
key: e
5) Chairman POF board has announced 30, 20, 10 and 5 scholarships for the students achieving 1st, 2nd, 3rd and 4th positions in professional exams of U.H.S. The central tendency of this data will be
a) 16.5
b) 15
c) 14
d) 10
e) 5
Key: b
6) birth record of obstetric ward of POF hospital for the month of july showed that
50infants (under weight) = <2500gm 150infants (normal) = >2500gm<400gm 30infants (over weight) = >400gm
This type of data is categorized as
a) Nominal
b) Ordinal
c) Discrete
d) Continuous
e) Dichotomous
Key: c
7) The data of distribution of <5mortality of Faisalabad in 2009 due to diarrhea, ARI, vaccine preventable diseases and other can be graphically represented by a) Pie chart b) Histogram c) Bar diagram d) Scatter diagram e) Pictogram
Key: a
8) The systolic blood pressures of 15 patients coming to a tertiary care hospital with stroke were recorded as follows 156,174,148,185,150,170,176,188,180,180,150,200,220,140 and 150 The mean of this data will be a) 140 b) 156 c) 164 d) 171 e) 183
Key: d
9) The data regarding the naturopathic complications of diabetes mellitus depending on the duration of illness was recorded in following 6 categories depending on the duration of illness with class interval of 5 class1 = 1-5years class11= 6-10 years class111= 11-15years Class IV = 16-20years Class V = 21-25years Class VI =>25 years
This data can be graphically represented by
a) Pie chart
b) Histogram
c) Bar diagram
d) Scatter diagram
e) Pictogram
Key: c
10) Marks obtained by the students of batch f in the subject of community medicine were as follows
220,210,240,180,185,200,170,250,50,75,195,205
The central tendency of this data would be
a) 175
b) 181
c) 185
d) 210
e) 220
Key: c
11) Birth weights of the babies of PIH patients were recorded to see the effect of PIH on fetal weight. The measures of the central tendency for the data obtained were as follows
Mean = 200gm
Median = 2500gm
Mode = 2800gm
If graphically represented this data will be
a) Normally distributed
b) Negatively skewed
c) Positively skewed
d) Bimodal
e) Poly modal
Key: b
12) The blood urea levels of the renal failure patients were recorded. The highest level was 110mg/dl and the lowest level was 50mg/dl. The range of the values will be
a) 40
b) 55
c) 60
d) 75
e) 80
Key: c
13) In a study on 100pregnant ladies to determine the average weight gain in pregnancy the mean of the sample was 14kg with a SD of 5kg.if the data is normally distributed the %age of the women that will have weight beyond the range of 4-24kg
a) 68%
b) 34%
c) 27%
d) 13.5%
e) 5%
Key: e
14) Suppose from a sampling frame of 1200 medical students, you have to conduct a survey on a sample of 100 students about their knowledge of hazards of smoking. The first value for the systematic random sampling
a) 11
b) 12
c) 13
d) 14
e) 15
Key: a
15) The data of a sample of 400 IHD patients with smoking for the last 10years was normally distributed around the mean with the SD of 8. The S.E would be
a) 0.2
b) 0.4
c) 0.8
d) 1.0
e) 1.4
Key: b
16) The mean serum cholesterol of a sample of 100 hypertensive patients was 175mg/dl with a SD of 15mg/dl. What would be 95% confidence interval for the population mean
a) 150-155
b) 163.3-169.5
c) 173.5-176.5
d) 180-189
e) 186.5-197.8
Key: c
