BCEMP Biostatistics Exam Questions with Correct Answers| Latest Update
Guaranteed Success
T/F: correctly identifying the type of data used in the study is most important for selecting a
statistical test TRUE
What are examples of discrete variables? Mortality: yes/no
Disease state: yes/no
NYHA Functional Class (I, II, III, IV)
Trauma Score
What are examples of continuous variables? Heart rate
Blood pressure
Time
Distance
What is the definition of a continuous variable? A variable that can take on any value within
a given range
T/F: scatterplots are important for correlation and regression when a line is best fit to the study
data points TRUE
T/F: an educated statement about an unknown population is commonly called an INFERENCE in
statistics TRUE
T/F: comparing the mean and median can provide information about the distribution of the
data TRUE
What is the relationship of the mean and median for data "skewed to the left"? Mean <
median
,What is the relationship of the mean and median for data "skewed to the right"? Mean >
median
T/F: the arithmetic average is also called "mean" TRUE
T/F: the mean should generally be used only for continuous and normally distributed data
TRUE
T/F: the mean is VERY SENSITIVE to outliers TRUE
What is a median? 1. 50th percentile
2. Midpoint of the values when placed from highest to lowest
T/F: a median is used for ordinal or continuous data TRUE
T/F: a median is SENSITIVE to outliers FALSE
T/F: a mode is the most common value in the data set TRUE
T/F: modes are useful for nominal, ordinal, and continuous data types TRUE
T/F: a standard deviation describes the variability/spread around the mean TRUE
What does a small vs large SD represent? A small SD indicates that the study values in the
data set are relatively close to the mean
, A large SD indicates that the study values are farther from the mean, indicating a higher
variability in the data-set
T/F: the empiric rule for normal distributions includes that 68% of the sample values are found
within +/- 1 SD, and 95% of the sample values are found within +/- 2 SDs, and 99% of the
sample values are found within +/- 3 SDs TRUE
T/F: the standard error of the mean (SEM) is an estimate of certainty that a calculated sample
mean represents the true mean of the population TRUE (inferential)
T/F: the SEM will always be smaller than the SD TRUE
The 95% CI is approx = mean +/- (1.96*SEM)
T/F: the median and the mean will be about equal for normally distributed data TRUE
T/F: hypothesis testing helps determine the likelihood of any observed differences between
groups being explained by chance (there is no difference) or representing a statistically
significant difference TRUE
What does the null (H_0) hypothesis represent? no difference between groups being
compared
Treatment A is NOT meaningfully different from Treatment B
What does failure to reject the null hypothesis mean? There is no statistically significant
difference between the groups; DOES NOT mean they are equal
T/F: in a superiority trial you WANT the null hypothesis to be rejected to show that there is a
difference between treatments TRUE
Guaranteed Success
T/F: correctly identifying the type of data used in the study is most important for selecting a
statistical test TRUE
What are examples of discrete variables? Mortality: yes/no
Disease state: yes/no
NYHA Functional Class (I, II, III, IV)
Trauma Score
What are examples of continuous variables? Heart rate
Blood pressure
Time
Distance
What is the definition of a continuous variable? A variable that can take on any value within
a given range
T/F: scatterplots are important for correlation and regression when a line is best fit to the study
data points TRUE
T/F: an educated statement about an unknown population is commonly called an INFERENCE in
statistics TRUE
T/F: comparing the mean and median can provide information about the distribution of the
data TRUE
What is the relationship of the mean and median for data "skewed to the left"? Mean <
median
,What is the relationship of the mean and median for data "skewed to the right"? Mean >
median
T/F: the arithmetic average is also called "mean" TRUE
T/F: the mean should generally be used only for continuous and normally distributed data
TRUE
T/F: the mean is VERY SENSITIVE to outliers TRUE
What is a median? 1. 50th percentile
2. Midpoint of the values when placed from highest to lowest
T/F: a median is used for ordinal or continuous data TRUE
T/F: a median is SENSITIVE to outliers FALSE
T/F: a mode is the most common value in the data set TRUE
T/F: modes are useful for nominal, ordinal, and continuous data types TRUE
T/F: a standard deviation describes the variability/spread around the mean TRUE
What does a small vs large SD represent? A small SD indicates that the study values in the
data set are relatively close to the mean
, A large SD indicates that the study values are farther from the mean, indicating a higher
variability in the data-set
T/F: the empiric rule for normal distributions includes that 68% of the sample values are found
within +/- 1 SD, and 95% of the sample values are found within +/- 2 SDs, and 99% of the
sample values are found within +/- 3 SDs TRUE
T/F: the standard error of the mean (SEM) is an estimate of certainty that a calculated sample
mean represents the true mean of the population TRUE (inferential)
T/F: the SEM will always be smaller than the SD TRUE
The 95% CI is approx = mean +/- (1.96*SEM)
T/F: the median and the mean will be about equal for normally distributed data TRUE
T/F: hypothesis testing helps determine the likelihood of any observed differences between
groups being explained by chance (there is no difference) or representing a statistically
significant difference TRUE
What does the null (H_0) hypothesis represent? no difference between groups being
compared
Treatment A is NOT meaningfully different from Treatment B
What does failure to reject the null hypothesis mean? There is no statistically significant
difference between the groups; DOES NOT mean they are equal
T/F: in a superiority trial you WANT the null hypothesis to be rejected to show that there is a
difference between treatments TRUE
