Quiz: Biostatistics and Epidemiology
Due Jun 25 at 11:59pm
Points 100
Questions 25
Time Limit 120 Minutes
Instructions
The quiz:
Covers the Learn material from Module 1: Week 1 - Module 6: Week 6.
Contains 25 multiple-choice and true/false questions.
Is limited to 2 hours.
Allows 1 attempt.
Is worth 100 points.
Submit this assignment by 11:59 p.m. (ET) on Sunday of Module 6: Week 6.
Attempt History
Attempt Time Score
LATEST Attempt 1 35 minutes 96 out of 100
Correct answers are hidden.
Score for this quiz: 96 out of 100
Submitted Jun 24 at 12:05pm
This attempt took 35 minutes.
Question 1
4 / 4 pts
You are planning to follow a group of weight loss challenge participants to determine the
effectiveness of the program. Only six individuals have enrolled. Their beginning weights in
pounds are 220, 225, 230, 233, 233, and 235. What is the range of weights?
220 to 235 pounds
10 pounds
15 pounds
5 pounds
Question 2
4 / 4 pts
Statistical tests are conducted to determine the probability of observing a difference within a
sample if no true difference exists within the population. Differences within a sample can occur
through randomly for a variety of reasons including simple sampling errors. A random difference
of 5% or less is not uncommon is generally not considered to be significant. Reporting this
probability is the primary output of statistical tests and is known as a
p-value < 0.05
p-value of 5
5% odds level
random probability outcome
Question 3
4 / 4 pts
How do you calculate the prevalence of a disease?
Number of contacts / number of new cases among contacts
Number of new cases during a specified period/size of population at start of period
Number of new cases during a specific period/time each person was observed, totaled for all
person
(All new and pre-existing cases during a given time period/Population during the same time
period) X 10n
Question 4
4 / 4 pts
A variable....?
is any characteristics, number, or quantity that can be measured or counted.
is the total number of new cases divided by the total population.
is a measure of incidence that incorporates time directly into the
denominator.
is any departure, subjective or objective, from a state of physiological or
psychological well-being.
Question 5
4 / 4 pts
Public health surveillance ...
is the cornerstone of public health practice.
covers infectious diseases, noninfectious health conditions, both infectious
and noninfectious diseases and health conditions, and risk factors and
exposures.
improves public health response, allowing systems to adapt to current and
future public health innovations.
All of the above
Question 6
4 / 4 pts
An incidence rate describes how quickly disease occurs in a population.
True
False
Question 7
4 / 4 pts
Three hundred and fifty adult males with diabetes are classified by age and weight as follows:
Age (years) Weight (kg)
60-69 70-79 80-89 ≥90
20-29 5 10 20 30
30-39 10 10 30 40
40-49 10 15 30 30
50-59 5 15 20 20
60-69 5 15 15 15
Find the probability that an individual is in the 50-69 year age interval.
14.2%
20.0%
31.4%
54.5%
Question 8
4 / 4 pts
Three hundred and fifty adult males with diabetes are classified by age and weight as follows:
Age (years) Weight (kg)
60-69 70-79 80-89 ≥90
20-29 5 10 20 30
30-39 10 10 30 40
40-49 10 15 30 30
50-59 5 15 20 20
60-69 5 15 15 15
Find the probability that an individual is in the 40-49 year age interval.
2.9%
24.3%
28.5%
33.3%
Question 9
4 / 4 pts
Three hundred and fifty adult males with diabetes are classified by age and weight as follows:
Age (years) Weight (kg)
60-69 70-79 80-89 ≥90
20-29 5 10 20 30
30-39 10 10 30 40
40-49 10 15 30 30
50-59 5 15 20 20
60-69 5 15 15 15
Find the probability that an individual in the 30-39 year age interval does not weigh over 90kg.
11.7%
14.3%
26.1%
55.6%
Question 10
4 / 4 pts
In an outbreak of gastroenteritis among attendees of a corporate
picnic, 99 persons ate potato salad, 30 of whom developed
gastroenteritis. Calculate the risk (incidence proportion) of illness
among persons who ate potato salad.
30.3%
52.9%
3.3%
69
Question 11
4 / 4 pts
The following information was extracted from Table 2 in the MMWR article, Prevalence of
healthy sleep duration among adults — United States, 2014 written by Liu Y, Wheaton AG,
Chapman DP, Cunningham TJ, Lu H, Croft JB.
Age-adjusted* percentage of adults who reported ≥7 hours sleep per
24-hour period, by state — Behavioral Risk Factor Surveillance System,
United States, 2014
State No.† % (95%
CI)§
Texas 14,950 67.0 (65.7–68.3)
Utah 14,719 69.2 (68.3–70.1)
Vermont 6,357 69.0 (67.4–70.4)
Virginia 9,225 64.0 (62.6–65.3)
Abbreviations: CI = confidence interval;
* Age-adjusted to the 2000 projected U.S. population aged ≥18 years.
† Unweighted sample of respondents. § Weighted percentage and 95% CI.
Assuming that adults need at least 7 hours of sleep in a 24-hour period for optimal health, what
can be stated concerning sleep among adults in Virginia compared to their counterparts in Texas,
Utah, and Vermont?
A significantly lower percentage of Virginias received adequate sleep compared to adults in the
other 3 states
A significantly higher percentage of Virginias received adequate sleep compared to the other 3
states
A lower percentage of Virginians reported over 7 hours of sleep per day, but since the confidence
levels overlap the finding is insignificant
Nothing can be stated about sleep among Virginians from the given data.
Question 12
4 / 4 pts
The likelihood of obtaining valid statistically significant results increases
as our sample size decreases
as our sample size increases
when we choose only cases that fit our theories
only if the confidence interval crosses zero
Question 13
4 / 4 pts
An example of a type of variable is:
Nominal
Continuous
Discrete
All of the Above
I Question 14
0 / 4 pts
On a symmetrical bell curve the midway point between the high and low values on the
distribution represents the
Mean
Mode
Median
All the above
Question 15
4 / 4 pts
Two populations are evaluated for blood pressure and the relative frequency of the diastolic
values are plotted on a graph. The graphs for the populations have a symmetrical distribution
with the same mean; however, the graph for Population A has a very narrow peak while the
graph for Population B has a wider base. Population A has
More members
Less members
Greater range
Smaller range
Question 16
4 / 4 pts
You are given a bag containing 50 marbles. The marbles are red, or green. There is one blue
marble in the bag. The odds of randomly picking a green marble from bag are 1:24. What is the
ratio of green marbles to red marbles in the bag?
1 green marble/23 red marbles
2 green marbles/47 red marbles
2 green marbles/48 red marbles
1 green marble/48 red marbles
Question 17
4 / 4 pts
What is prevalence?
is the proportion of a population who have a specific characteristic in a given time
period.
as any departure, subjective or objective, from a state of physiological or
psychological well-being.
is the proportion of an initially disease-free population that develops disease,
becomes injured, or dies during a specified (usually limited) period of time.
is the total number of new cases divided by the total population.
Question 18
4 / 4 pts
You recently collected data for a semi-annual study about exposure to workplace noise exposure
for adults from an audiology clinical file at the corporate occupational medicine clinic. You have
1347 files, one for each employee working in an area with an exposure to ambient noise
exceeding the OSHA threshold of 8-hour time-weighted average sound level (TWA) of 85
decibels. The data are:
sex Age Group Number of days above
TWA
Male (n=1026) 20 -29 years (n=220) <30 days (n=17)
Female (n=321) 30-39 years (n=612) 30-90 days(n=31)
40-49 years (n=358) 91-120 days (n=321)
50-59 years (n=157) >120 days (n=978)
You randomly select one file. What is the probability of selecting a female’s file?
23.8%
31.3%
76.2%
50%
Question 19
4 / 4 pts
In a bag containing 50 red, green, and blue marbles the marble color would be considered a
Dichotomous variable
Nominal variable
Continuous variable
Discrete variable
Question 20
4 / 4 pts
A survey of 728 students at a local elementary school determined that half the students were boys
and half were girls. Among the girls 49% are blondes, 3% are red-heads, 10% have black hair,
and the remainder have chestnut-brown hair. Among the boys 40% are blondes, 2% are red-
heads, 8% have black hair, and the remainder have chestnut-brown hair. What is the most
commonly represented category of student in the school?
Blonde haired girls
Blonde haired boys
Chestnut-brown haired girls
Chestnut-brown haired boys
Question 21
4 / 4 pts
You are planning to follow a group of weight loss challenge participants to determine the
effectiveness of the program. Only six individuals have enrolled. Their beginning weights in
pounds are 220, 225, 230, 233, 233, and 235. What is the mean value of participant weights?
233 pounds
231.5 pounds
230.4 pounds
229.3 pounds
Question 22
4 / 4 pts
You recently collected frequency data for a semi-annual study about exposure to workplace noise
exposure for adults from an audiology section of a corporate occupational medicine clinic. You
have 1347 files, one for each employee working in an area with an exposure to ambient noise
exceeding the OSHA threshold of 8-hour time-weighted average sound level (TWA) of 85
decibels. The initial analysis of data yields the following frequencies for the various variables:
sex Age Group Number of days above
TWA
Male (n=1026) 20 -29 years (n=220) <30 days (n=17)
Female (n=321) 30-39 years (n=612) 30-90 days(n=31)
40-49 years (n=358) 91-120 days (n=321)
50-59 years (n=157) >120 days (n=978)
You randomly select one file. What is the probability that it belongs to an individual who is in
the 20-39 year age interval?
16.3%
28%
45.4%
61.8%
Question 23
4 / 4 pts
Range is a simple measure of
Centrality
Modality
Variability
Relative frequency
Question 24
4 / 4 pts
The following data has been obtained from a community survey investigating the association of
exposure to small particles from indoor wood fires for heating and cooking in Romania and
development of chronic respiratory disease (COPD). The population of the Romanian town is
7300. A representative sample of 10% of the population was questioned. The sample included
500 people who use wood indoors for cooking and heating. The remainder do not use wood for
either purpose. Exactly 90% of the people in the survey suffer from COPD. Among those with
exposure to indoor wood burning on 2 people did not have COPD. Use a 2x2 table to evaluate
the data and determine the number of people with COPD who were not exposed to indoor wood
smoke.
657 people
498 people
159 people
71 people
Question 25
4 / 4 pts
What is Healthy People?
Healthy People is a dieting website that provides nutrition information.
Healthy People provides science-based, 10-year national objectives for improving the health of all
Americans.
Healthy People is a mental health and wellness website.
Healthy People is a private website selling essential health-related products.
