quiz midterm
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School
Liberty University *
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Course
501
Subject
Health Science
Date
Feb 20, 2024
Type
docx
Pages
20
Uploaded by SuperHumanStar18109
Score for this quiz:
150
out of 150
Submitted Feb 9 at 1:51pm
This attempt took 176 minutes.
Question 1
3
/ 3
pts
A newly developed medical procedure to prevent death in women who give birth and experience eclampsia has a 97.5% success rate of saving the woman’s life. If a doctor uses this medical procedure in 6 women who experience eclampsia and have no other comorbid conditions, the probability
that all 6 women will survive is approximately 0.859.
True
False
Question 2
3
/ 3
pts
In which situation would it be most appropriate to use the mean of the set of numbers to describe the data set instead of the median?
165, 165, 177, 178, 186, 199, 211
152, 157, 159, 163, 164, 165, 976
0, 57, 847, 859, 866, 866, 872
0, 899, 906, 912, 915, 917, 919
Question 3
3
/ 3
pts
An investigator wants to assess whether smoking is a risk factor for pancreatic cancer. Electronic medical records at a local hospital will be used
to identify 50 patients with pancreatic cancer. One hundred patients who are
similar but free of pancreatic cancer will also be selected. Each participant’s medical record will be analyzed for smoking history. Identify the type of study proposed
A case-control study
A case series
A retrospective cohort study
A prospective cohort study
Question 4
3
/ 3
pts
A new drug is released to market and it has been determined that the drug is
responsible for causing hypertension among those individuals who take the drug. If 30,276 individuals were prescribed the drug in its first year on the market and 17,620 individuals developed hypertension, what is the point prevalence of hypertension among those individuals prescribed the drug, after the drug’s first year on the market?
5.82000
0.05820
0.58200
0.00582
Question 5
3
/ 3
pts
The margin of error in a research study is indicative of the precision and accuracy of the research results obtained in the study.
True
False
Question 6
3
/ 3
pts
Incidence reflects the likelihood of developing a disease among a group of participants free of the disease who are considered at risk of developing the disease over a specified observation period; prevalence involves estimating the proportion of people who have disease at a point in time.
True
False
Question 7
3
/ 3
pts
The mean is the 50th percentile of any normal distribution.
True
False
Question 8
3
/ 3
pts
A newly proposed endoscopy method used to screen for colon cancer is tested among a random sample of the population. Given that 16 individuals
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from a test population of 100,000 individuals has colon cancer and 14 of the 16 individuals test positive for colon cancer, the researchers should determine the sensitivity of the newly proposed screening method is .875.
True
False
Question 9
3
/ 3
pts
The median of a group of individuals’ BMIs whose BMIs are 20.47, 21.92, 23.32, 23.41, 25.7, and 30.1 is approximately 24.15.
True
False
Question 10
3
/ 3
pts
Case-control study, prospective cohort study, cross-over trial, and retrospective cohort study are all examples of observational study designs.
True
False
Question 11
3
/ 3
pts
The mean measure of high density lipoprotein (HDL), or good cholesterol, is 54 with a standard deviation of 17 in patients over age 50. If the HDL values are obtained from a sample of 32 individuals, the probability of getting a mean HDL value over 62 is 0.049.
True
False
Question 12
3
/ 3
pts
After attending a church cookout, a number of the attendees are admitted to
the emergency room with nausea, vomiting, and diarrhea. After discovering all the individuals admitted to the ER consumed the egg salad at the event, the leftover egg salad was tested and found to be positive for salmonella. If 83 individuals consumed the egg salad and 49 individuals were admitted to the ER with salmonella, what was the cumulative incidence of salmonella assuming that the 49 individuals admitted to the ER were the only ones to be
affected by the bacteria?
0.590
0.059
0.410
0.041
Question 13
3
/ 3
pts
True/False? Five hundred people are enrolled in a 10-year cohort study. At the start of the study, 50 have diagnosed CVD. Over the course of the study, 40 people who were free of CVD at baseline develop CVD. The prevalence of CVD at 10 years is 10%.
True
False
Question 14
3
/ 3
pts
Drug manufactures of Drug X, which was released on the market 5 years ago
to treat Crohn’s disease, have noticed that many individuals treated with the
drug have developed drug-induced lupus. A cohort study was conducted for post-marketing surveillance. It has documented that 6 individuals have developed drug-induced lupus over the course of the past 5 years. If 1 individual developed the disease at the 1-year mark, 3 developed the disease at the 2-year mark, 1 developed the disease at the 3-year mark, and the final individual developed the disease at the 4-year mark, what is the incidence rate of drug-induced lupus?
0.9571
0.4290
0.5710
0.0429
Question 15
3
/ 3
pts
A study is designed to evaluate the impact of a daily multivitamin on students’ academic performance. One hundred sixty students are randomly assigned to receive either the multivitamin or a placebo and are instructed to take the assigned drug daily for 20 days. On day 20, each student takes a standardized exam and the mean exam scores are compared between groups. This study is an example of a Randomized Control trial.
True
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False
Question 16
3
/ 3
pts
If there are outliers, then the mean will be greater than the median.
True
False
Question 17
3
/ 3
pts
Biostatistics is integral to the practice of public health because it allows public health professionals to accurately monitor and track the prevalence of
disease within a population.
True
False
Question 18
3
/ 3
pts
A healthcare provider notices an outbreak of foodborne illness among individuals who attended a holiday cookout. Which study type would be most
beneficial in identifying the source of the outbreak?
A retrospective cohort study
A cross-sectional survey
A case-control study
A case series
Question 19
3
/ 3
pts
A researcher has a hypothesis that a specific drug may have a higher prevalence of side effects among members of the African American population than members of the Caucasian population. Which statistical technique might the researcher want to use when designing a study to test their hypothesis?
Randomization
Stratification
Matching
Crossover matching
Question 20
3
/ 3
pts
The mean is a better measure of location (central tendency) when there are no outliers.
True
False
Question 21
3
/ 3
pts
The relative risk of developing lung cancer among individuals who smoke is 15.0. Which of the following is the most accurate interpretation of this information?
Individuals who smoke are 15.0% more likely to develop lung cancer than individuals who do not smoke.
Individuals who have lung cancer are 15.0 times more likely to smoke than individuals who do not have lung cancer.
Individuals who have lung cancer are 15.0% more likely to smoke than individuals who do not have lung cancer.
Individuals who smoke are 15.0 times more likely to develop lung cancer than individuals who do not smoke.
Question 22
3
/ 3
pts
With a binomial distribution with
n
= 25 and
p
= 0.48, which is larger?
P(9 successes)
P(10 successes)
P(20 successes)
P(12 successes)
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Question 23
3
/ 3
pts
The most widely used measure of variability for a continuous variable is called the
standard deviation.
True
False
Question 24
3
/ 3
pts
If the odds of catching the flu among individuals who take vitamin C is 0.0342 and the odds of catching the flu among individuals not taking vitamin
C is 0.2653, then the individuals not taking vitamin C are 7.7573 times more likely to catch the flu than individuals taking vitamin C.
True
False
Question 25
3
/ 3
pts
The 90th percentile of the standard normal distribution is 1.645.
True
False
Question 26
3
/ 3
pts
The following table shows the results of a screening test hypothesized to detect persons at risk for side effects of a new cosmetic surgery. Compute the specificity of the test.
Side effects
present
Side effects
absent
Screen positive
12
4
Screen negative
80
234
Your Answer:
234/4+238 = .098319328
Question 27
3
/ 3
pts
A clinical trial designed to show the efficacy of a new drug in reducing progression to hypertension reports the following data. Using this information, compute the relative risk of progression to hypertension among patients receiving the new drug as compared to the placebo.
New Drug
Placebo
Sample size
200
200
Progression to hypertension
11%
21%
Your Answer:
.11(200) / 21.(200) = .52380952
Question 28
3
/ 3
pts
A ferritin test is a popular test to measure a person’s current iron stores. In women, ferritin is approximately normally distributed with a mean of 89 ng/mL and a standard deviation of 23 ng/mL. If 50 women are tested, what is the probability that the mean ferritin exceeds 90?
Your Answer:
The probability that the mean ferritin exceeds 90 is 38% (.3793).
Question 29
3
/ 3
pts
A new non-invasive screening test is proposed that is claimed to be able to identify patients with impaired glucose tolerance based on a battery of questions related to health behaviors. The new test is given to 75 patients. Based on each patient’s responses to the questions they are classified as positive or negative for impaired glucose tolerance. Each patient also submits a blood sample
and their glucose tolerance status is determined. The results are tabulated below. What is the sensitivity of the screening test?
Screening Test
Impaired Glucose
Tolerance
Not Impaired
Positive
23
17
Negative
9
41
Your Answer:
23 / (23+9) = 23 / 32 = 0.71875
Question 30
3
/ 3
pts
An experimental drug has been shown to be 80% effective in eliminating symptoms of allergies in animal studies. A small human study involving eight participants is conducted. What is the probability that the drug is effective on half of the participants?
Your Answer:
x
n
p
4
8
0.8
0.045875
The probability that the drug is effective on half of participants is 4.58%
Question 31
3
/ 3
pts
An investigator wants to test whether exposure to secondhand smoke before 1 year of life is associated with development of childhood asthma (defined as asthma diagnosed before 5 years of age). Give two possible study designs.
Your Answer:
1. Cohort Study
2. Case-control study
Question 32
3
/ 3
pts
A pilot study is run to investigate the effect of a lifestyle intervention designed to increase medication adherence in patients with HIV. Medication adherence is measured as the percentage of prescribed pills that are taken over a one-week observation period. Ten patients with HIV
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agree to participate and their medication adherence before and after the intervention are shown below. Compute the standard deviation of the difference in adherence before versus after the intervention.
Participant ID
Before Intervention
After Intervention
1
75%
79%
2
83%
84%
3
66%
70%
4
79%
68%
5
88%
90%
6
66%
78%
7
55%
60%
8
93%
90%
9
97%
90%
10
91%
95%
Your Answer:
Standard deviation before the intervention is 13.00038
Standard deviation after the intervention is 10.90138.
Difference in mean is 6.57
Question 33
3
/ 3
pts
Approximately 35% of obese patients develop diabetes. Answer the following questions if a physician sees 12 patients who are obese. What is the probability that half of them will develop diabetes?
Your Answer:
6
12
0.35
0.128103318
The probability that half of them will develop diabetes is 12.8%
Question 34
3
/ 3
pts
A study is conducted to test a new drug claimed to reduce diastolic blood pressure in adults with a history of coronary heart disease. What is the most efficient study to test whether the drug reduces diastolic blood pressure?
Your Answer:
Randomized control trial
Question 35
3
/ 3
pts
A study is run to estimate the incidence of atrial fibrillation (AF) in men and women over the age
of 60. Development of atrial fibrillation was monitored over a 10-year follow-up period. The data are summarized below. Using this data, compute the cumulative incidence of AF in men and
in women respectively.
Developed AF
Did not Develop AF
Men
133
6153
Women
79
7167
Your Answer:
For men, (133/6,286) x 100 = 2.11581292
For women, (79/7,246) x 100 = 1.09025669
Question 36
3
/ 3
pts
A study is run to investigate body mass index (BMI) in children living in urban neighborhoods. Based on the following data: compute the sample mean, the sample standard deviation, and the median.
29 21 27 31 35 26 33 30 24
Your Answer:
28.44444
4.419025
29
Mean - 28.4, standard deviation - 4.419, and median 29
Question 37
3
/ 3
pts
Body mass index (BMI) in children is approximately normally distributed with a mean of 24.5 and a standard deviation of 6.2. In a random sample of 10 children, what is the probability that their mean BMI exceeds 25?
Your Answer:
39.7%
The probability that their mean BMI exceeds 25 is 39.7%
Question 38
3
/ 3
pts
Four hundred melanoma patients were diagnosed according to the type of skin cancer and the location of the skin cancer. This data is presented below. What proportion of patients had Hutchinson’s melanomic freckle?
Location
Type
Head and
Neck
Trunk
Extremities
Total
Hutchinson’s melanomic freckle
22
2
10
34
Indeterminate
11
17
28
56
Nodular
19
33
73
125
Superficial spreading melanoma
16
54
115
185
Total
68
106
226
400
Your Answer:
34/400 = .085 = 8.5%
The proportion of patients who had Hutchinson's melanomic freckle is 8.5%.
Question 39
3
/ 3
pts
Glucose levels in patients free of diabetes are assumed to follow a normal distribution with a mean of 113 and a standard deviation of 13. What proportion of patients have glucose levels exceeding 120?
Your Answer:
0.295129226
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The proportion of patient that have glucose level exceeding 120 is 29.5%
Question 40
3
/ 3
pts
Suppose that the probability that a child living in an urban area in the United States is obese is 22%. If a social worker sees 20 children living in urban areas, answer the following: What is the probability that none are obese?
Your Answer:
The probability is 0.6% that none are obese.
Question 41
3
/ 3
pts
The data shown below describe children in four countries in terms of adequate dental care. What is the probability that a child from Mexico has adequate dental care?
Adequate Dental Care
Inadequate Dental Care
United Kingdom
2539
176
United States
4563
209
France
1298
307
Mexico
2874
256
Your Answer:
0.91821
91.8% is the probability that a child from Mexico has adequate dental care.
Question 42
3
/ 3
pts
The faculty and staff at Dana-Farber Cancer Institute in Boston are required to undergo a tuberculosis test each year. Use the following table to answer the questions below. If a Dana-
Farber faculty or staff worker goes in to have a TB test, what is the chance of him/her getting a negative test result?
Test Result
Tuberculosis
Yes No
Total
Positive
4995
99,950
104,945
Negative
5
9,895,050
9,895,055
Total
5,000
9,995,000
10,000,000
Your Answer:
9,895,050/10,000,000 = .9895
98.95% chance of him/her getting negative test result
Question 43
3
/ 3
pts
The following are body mass index (BMI) scores measured in 12 patients who are free of diabetes and participating in a study of risk factors for obesity. Body mass index is measured as the ratio of weight in kilograms to height in meters squared. Using the following data, compute the mean BMI, the standard deviation of BMI, the median BMI, and the Q1 and Q3.
32 38 24 33 25 27 42 29 35 40 35 28
Your Answer:
Mean
32.33333
St. Dev
5.882692
Median
32.5
Q1
27.75
Q3
35.75
Question 44
3
/ 3
pts
The following are grade point averages measured in a sample of 8 undergraduate students who are applying to graduate schools in public health. Compute the sample mean, the sample standard
deviation, and the sample median.
2.99 3.13 3.61 2.95 3.05 3.00 3.41 3.28
Your Answer:
Mean
3.1775
Median
3.13
Std Dev
0.2356
Question 45
3
/ 3
pts
The following data were collected in a survey of 8th graders and summarize their cell phone status. What proportion of the 8th graders have cell phones?
No cell
phone
Conventional cell phone
user
Smart phone
user
Boys
50
65
33
Girls
31
76
27
Your Answer:
201/282 = .71276
71.28% of 8th graders have cell phones
Question 46
3
/ 3
pts
The following table shows the numbers of patients classified as underweight, normal weight, overweight and obese according to their diabetes status. What is the probability that a patient selected at random is obese?
Underweight
Normal
Weight
Overweight
Obese
Diabetes
8
34
65
43
No Diabetes
12
85
93
40
Your Answer:
83/380 = .21842
21.84% is the probability that a patient selected at random is obese.
Question 47
3
/ 3
pts
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The following table shows the distribution of BMI in children living in United States and European urban neighborhoods. (The data are in millions.) What is the probability that a child living in a U.S. urban neighborhood is obese?
Neighborhood
Normal Weight
Overweight
Obese
United States
125
50
40
Europe
101
42
21
Your Answer:
40/215 = .18604
18.6% is the probability that a child living in a US urban neighborhood is obese
Question 48
3
/ 3
pts
The following table shows the results of a screening test hypothesized to identify persons at risk for a rare blood disease. Compute the False Positive Fraction of the test.
No Disease
Disease
Screen Negative
1351
20
Screen Positive
39
41
Your Answer:
39 / (39+1351) = .02805755
Question 49
3
/ 3
pts
The gestation period for human births can be taken as normally distributed with a mean of 256 days and a standard deviation of 16 days. If a gestation period is 276 days, what percentile among human births is this?
Your Answer:
276
256
16
0.894350226
89.4% percentile
Question 50
3
/ 3
pts
The risk of hepatoma among alcoholics without cirrhosis of the liver is 32%. Suppose we observe 9 alcoholics without cirrhosis. What is the probability that exactly one of these 9 people have a hepatoma?
Your Answer:
1
9
0.32
0.131663
Quiz Score:
150
out of 150