Introduction to Biostatistics BCQs

1. The primary goal of descriptive statistics is to:
• a) Make inferences about a population based on a sample
• b) Test hypotheses about relationships between variables
• c) Summarize and present data in a meaningful way
• d) Predict future outcomes based on past trends
• e) Determine the cause-and-effect relationship between variables
1. Which of the following is an example of a continuous variable?
• a) Number of hospital admissions in a day
• b) Number of children in a family
• d) Gender (male/female)
• e) Type of occupation
1. The difference between a population and a sample is that:
• a) A population is always larger than a sample
• b) A sample is always representative of the population
• c) A population includes all members of a defined group, while a sample is a subset of that group
• d) A population is used for inferential statistics, while a sample is used for descriptive statistics
• e) There is no difference between the two
1. Which of the following is NOT a measure of central tendency?
• a) Mean
• b) Median
• c) Mode
• d) Range
• e) All of the above are measures of central tendency
1. The process of drawing conclusions about a population based on a sample is called:
• a) Descriptive statistics
• b) Data collection
• c) Inferential statistics
• d) Sampling
• e) Data analysis
1. Which type of variable allows for ranking or ordering of categories?
• a) Nominal
• b) Ordinal
• c) Interval
• d) Ratio
• e) Continuous
1. The collection, organization, summarization, analysis, and interpretation of data is the definition of:
• a) Biostatistics
• b) Statistics
• c) Epidemiology
• d) Public Health
• e) Data Science
1. A characteristic that takes on different values in different persons, places, or things is called a
• a) Variable
• b) Data
• c) Statistic
• d) Parameter
• e) Constant
1. Which of the following is an example of a qualitative variable?
• a) Age
• b) Weight
• c) Marital status
• d) Blood pressure
• e) Temperature
1. A numerical value that describes a population is called:
• a) Parameter
• b) Statistic
• c) Variable
• d) Data
• e) Constant
1. A researcher is studying the average BMI of adults in a city. The average BMI calculated from a sample of 1000 adults is:
• a) Parameter
• b) Statistic
• c) Variable
• d) Data
• e) Constant
2. A public health survey categorizes respondents’ income levels into “low,” “middle,” and “high.” This is an example of a (n) _____ variable.
• a) Nominal
• b) Ordinal
• c) Interval
• d) Ratio
• e) Continuous
3. In a study on the effects of a new drug, the number of patients who experience side effects is a _____ variable.
• a) Continuous
• b) Discrete
• c) Ordinal
• d) Nominal
• e) Ratio
4. A researcher wants to study the relationship between smoking and lung cancer. Smoking status (smoker/non-smoker) is a _____ variable.
• a) Nominal
• b) Ordinal
• c) Interval
• d) Ratio
• e) Continuous
5. The temperature measured in Celsius is an example of a (n) _____ variable.
• a) Nominal
• b) Ordinal
• c) Interval
• d) Ratio
• e) Discrete
6. You are conducting a survey to gather information about the health behaviors of a community. You collect data on variables such as age, gender, smoking status, exercise frequency, and dietary habits. Which of these variables are categorical, and which are numerical?
• a) Categorical: Age, gender, smoking status, exercise frequency. Numerical: Dietary habits
• b) Categorical: Gender, smoking status, exercise frequency. Numerical: Age, dietary habits
• c) Categorical: Gender, smoking status, exercise frequency. Numerical: Age
• d) Categorical: Smoking status, exercise frequency. Numerical: Age, gender, dietary habits
7. In a clinical trial, researchers are testing a new medication to lower blood pressure. They measure the blood pressure of participants before and after the treatment. What type of variable is blood pressure in this context?
• a) Nominal
• b) Ordinal
• c) Interval
• d) Ratio
8. A study is investigating the association between obesity and diabetes. Body Mass Index (BMI) is used to classify individuals as underweight, normal weight, overweight, or obese. What type of variable is BMI in this scenario?
• a) Nominal
• b) Ordinal
• c) Interval
• d) Ratio
9. A researcher is analyzing data on the number of new COVID-19 cases reported each day in a particular region. What type of variable is the number of new cases?
• a) Continuous
• b) Discrete
• c) Ordinal
• d) Nominal
10. A study collects the BMI of 100 patients in a clinic. What type of statistics would be used to summarize the average BMI?
• a) Inferential Statistics
• b) Descriptive Statistics
• c) Nominal Statistics
• d) Qualitative Statistics
• e) Continuous Statistics
11. Which of the following represents a population parameter?
• a) Sample mean of a class
• b) Mean weight of all children in a school
• c) Standard deviation of a sample
• d) Sample median
• e) Confidence interval of a sample
12. In a survey, 200 adults are asked about their smoking status. What type of variable is smoking status?
• a) Continuous
• b) Discrete
• c) Nominal
• d) Ordinal
• e) Interval
13. What is the probability of randomly selecting a person who has blood pressure categorized as “high” if 25 out of 100 individuals have high blood pressure?
• a) 0.15
• b) 25
• c) 0.50
• d) 0.75
• e) 1.00
14. A researcher calculates the average age of a sample of patients. What is this value called?
• a) Population Parameter
• b) Ordinal Data
• c) Sample Statistic
• d) Nominal Data
• e) Continuous Data
15. If a dataset has a mean of 50 and a standard deviation of 5, what is the z-score for a value of 60?
• a) 1.5
• b) 0
• c) 2.5
• d) 3.0
• e) 4.0
16. What type of data is recorded when measuring the heights of students in a class?
• a) Nominal
• b) Ordinal
• c) Continuous
• d) Discrete
• e) Categorical
17. In biostatistics, which type of variable is characterized by having whole numbers only?
• a) Continuous
• b) Interval
• c) Discrete
• d) Ratio
• e) Nominal
18. A health survey classifies weight into categories: underweight, normal, overweight, and obese. What type of variable is this?
• a) Continuous
• b) Ordinal
• c) Discrete
• d) Nominal
• e) Interval
19. A clinical trial finds that 60 out of 150 patients responded to a new treatment. What is the response rate?
• a) 20%
• b) 30%
• c) 40%
• d) 50%
• e) 60%
20. In a dataset, if the mode is 20, the median is 25, and the mean is 30, what does this suggest about the distribution?
• a) Symmetric
• b) Positively Skewed
• c) Negatively Skewed
• d) Bimodal
• e) Uniform
21. Which of the following represents a continuous variable?
• a) Number of children in a family
• b) Number of patients admitted per day
• c) Blood pressure in mmHg
• d) Number of teeth
• e) Number of hospital beds
22. If a study reports that the mean age of participants is 35 years with a margin of error of ±3 years, what is the confidence interval?
• a) 30-40 years
• b) 32-38 years
• c) 33-37 years
• d) 34-36 years
• e) 31-39 years
23. What type of measurement scale is used when categorizing a variable as “Male” or “Female”?
• a) Ordinal
• b) Nominal
• c) Interval
• d) Ratio
• e) Continuous
24. Which of the following best describes inferential statistics?
• a) Summarizing data
• b) Making predictions about a population based on a sample
• c) Measuring central tendency
• d) Displaying data in graphs
• e) Sorting data into categories
25. Which type of data would be best visualized using a bar chart?
• a) Continuous data
• b) Categorical data
• c) Interval data
• d) Ratio data
• e) Discrete data
26. In hypothesis testing, what does the p-value represent?
• a) The mean of the sample
• b) The probability of observing the data given that the null hypothesis is true
• c) The standard deviation of the sample
• d) The correlation between variables
• e) The effect size
27. Which branch of statistics deals with collecting and presenting data without making any conclusions?
• a) Inferential
• b) Descriptive
• c) Predictive
• d) Causal
• e) Analytical
28. What is the primary purpose of random sampling in research?
• a) To increase the sample size
• b) To reduce the variability
• c) To ensure each member of the population has an equal chance of being selected
• d) To increase the mean
• e) To control confounding variables
29. Which of the following best describes the concept of a ‘variable’ in biostatistics?
• a) A characteristic that can vary among individuals
• b) A fixed value in a population
• c) A constant number
• d) A single measurement
• e) An outcome of interest
30. What is the main reason for using a control group in an experiment?
• a) To randomize the study
• b) To compare results against a standard or baseline
• c) To increase sample size
• d) To ensure variability
• e) To establish a hypothesis
31. Which type of error occurs when a true null hypothesis is incorrectly rejected?
• a) Type I error
• b) Type II error
• c) Sampling error
• d) Measurement error
• e) Experimental error