EPIDEMIOLOGY FINAL EXAM
QUESTIONS WITH COMPLETE
SOLUTIONS
The expression used to categorize how severe a disease is - ANSWER-Virulence
A propagated epidemic is usually the result of what type of exposure? - ANSWER-
person to person spread
Factor A alone causes disease - ANSWER-Necessary AND Sufficient
Factor A OR Factor B OR Factor C all cause the disease without help - ANSWER-Not
Necessary BUT Sufficient
Factor A and Factor B work together to cause the disease - ANSWER-Necessary and
NOT Sufficient
Factor A combined with Factor M causes the disease, but so does Factor B combined
with Factor F - ANSWER-Not Necessary OR Sufficient
Which measure of central tendency represents the values that occur most frequently? -
ANSWER-Mode
Which measure of central tendency has half of the observations below it, and half above
it? - ANSWER-Median
"Gender" is considered which type of variable? - ANSWER-nominal
Which type of data is the most "powerful" and can be used in most situations? -
ANSWER-ratio
Definition of Mean - ANSWER-The average of the numbers. To calculate: add up all the
numbers, then divide by how many numbers there are.
Calculate the Median - ANSWER-Put all the numbers in numerical order. If there is an
odd number of results, the median is the middle number. if there is even numbers then it
is the sum of the middle two divided by two.
Calculate the Mode - ANSWER-put the numbers in order, then count how many of each
number. A number that appears most often is the mode.
How do you find the range in data? - ANSWER-The range of a set of data is the
difference between the highest and lowest values in the set. To find the range, first
, order the data from least to greatest. Then subtract the smallest value from the largest
value in the set.
Categorical data - ANSWER-(category) has no numerical value. Also known as
qualitative data (quality not a quantity). Divided into two types, Nominal and ordinal.
Nominal data - ANSWER-no inherent numerical value (nom=name; has to have a name
because there are no numbers)Ex. race, gender, zip code.
Ordinal data - ANSWER-no inherent numerical value. Consists of categories that can be
ranked. Ex. cancer, education level
Continuous data - ANSWER-does have inherent numerical value. Also known as
quantitative data (deals with quantity no a quality) divided into two types: interval and
ratio
Interval Data - ANSWER-Consists of numbers that can be placed on a number line. But
there won't be a clear zero on that line (interval=equally spaced units). Ex. dates there
is no 0 point on a number line of dates.
Ratio Data - ANSWER-Numbers that can be placed on a number line. Any number of
measurement with a 0 point. Only ratio data can calculate mean, standard deviation,
etc.
-1 or +1 deviations away from the mean - ANSWER-34.13% and 68.26%
-2 or +2 deviations away from the mean - ANSWER-13.59% and 95.44%
-3 or +3 deviations away from the mean - ANSWER-2.14% and 99.72%
Comparing numbers and rates of illness in a community, rates are preferred for: -
ANSWER-Estimating subgroups at highest risk
A cohort study differs from a case-control study in that: - ANSWER-Subjects are
enrolled or categorized on the basis of their exposure status in a cohort study but not in
a case-control study
A reservoir of an infectious agent can be: - ANSWER-An asymptomatic human
The environment
An animal
A symptomatic human
Indirect transmission does not include which of the following? - ANSWER-Doorknobs or
toilet seats
Droplet spread
QUESTIONS WITH COMPLETE
SOLUTIONS
The expression used to categorize how severe a disease is - ANSWER-Virulence
A propagated epidemic is usually the result of what type of exposure? - ANSWER-
person to person spread
Factor A alone causes disease - ANSWER-Necessary AND Sufficient
Factor A OR Factor B OR Factor C all cause the disease without help - ANSWER-Not
Necessary BUT Sufficient
Factor A and Factor B work together to cause the disease - ANSWER-Necessary and
NOT Sufficient
Factor A combined with Factor M causes the disease, but so does Factor B combined
with Factor F - ANSWER-Not Necessary OR Sufficient
Which measure of central tendency represents the values that occur most frequently? -
ANSWER-Mode
Which measure of central tendency has half of the observations below it, and half above
it? - ANSWER-Median
"Gender" is considered which type of variable? - ANSWER-nominal
Which type of data is the most "powerful" and can be used in most situations? -
ANSWER-ratio
Definition of Mean - ANSWER-The average of the numbers. To calculate: add up all the
numbers, then divide by how many numbers there are.
Calculate the Median - ANSWER-Put all the numbers in numerical order. If there is an
odd number of results, the median is the middle number. if there is even numbers then it
is the sum of the middle two divided by two.
Calculate the Mode - ANSWER-put the numbers in order, then count how many of each
number. A number that appears most often is the mode.
How do you find the range in data? - ANSWER-The range of a set of data is the
difference between the highest and lowest values in the set. To find the range, first
, order the data from least to greatest. Then subtract the smallest value from the largest
value in the set.
Categorical data - ANSWER-(category) has no numerical value. Also known as
qualitative data (quality not a quantity). Divided into two types, Nominal and ordinal.
Nominal data - ANSWER-no inherent numerical value (nom=name; has to have a name
because there are no numbers)Ex. race, gender, zip code.
Ordinal data - ANSWER-no inherent numerical value. Consists of categories that can be
ranked. Ex. cancer, education level
Continuous data - ANSWER-does have inherent numerical value. Also known as
quantitative data (deals with quantity no a quality) divided into two types: interval and
ratio
Interval Data - ANSWER-Consists of numbers that can be placed on a number line. But
there won't be a clear zero on that line (interval=equally spaced units). Ex. dates there
is no 0 point on a number line of dates.
Ratio Data - ANSWER-Numbers that can be placed on a number line. Any number of
measurement with a 0 point. Only ratio data can calculate mean, standard deviation,
etc.
-1 or +1 deviations away from the mean - ANSWER-34.13% and 68.26%
-2 or +2 deviations away from the mean - ANSWER-13.59% and 95.44%
-3 or +3 deviations away from the mean - ANSWER-2.14% and 99.72%
Comparing numbers and rates of illness in a community, rates are preferred for: -
ANSWER-Estimating subgroups at highest risk
A cohort study differs from a case-control study in that: - ANSWER-Subjects are
enrolled or categorized on the basis of their exposure status in a cohort study but not in
a case-control study
A reservoir of an infectious agent can be: - ANSWER-An asymptomatic human
The environment
An animal
A symptomatic human
Indirect transmission does not include which of the following? - ANSWER-Doorknobs or
toilet seats
Droplet spread
