LATEST WGU C784 APPLIED HEALTHCARE
STATISTICS OA Final Exam Newest Exam
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QUESTION 1
A researcher is examining the average systolic blood pressure of a
sample of 150 patients. The mean systolic blood pressure is 128 mmHg
with a standard deviation of 14 mmHg. What is the standard error of
the mean for this sample?
A) 1.14
B) 0.09
C) 14.00
D) 0.36
Answer: A) 1.14
Explanation: The standard error of the mean (SEM) is calculated by
dividing the standard deviation by the square root of the sample size.
The formula is SEM = s / √n. Here, s = 14 and n = 150. The square root of
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150 is approximately 12.25. Dividing 14 by 12.25 gives 1.14. This value
represents the standard deviation of the sampling distribution of the
sample mean, which quantifies the precision of the sample mean as an
estimate of the population mean.
QUESTION 2
Which measure of central tendency is most appropriate for a skewed
distribution of healthcare costs?
A) Mean
B) Median
C) Mode
D) Range
Answer: B) Median
Explanation: In a skewed distribution, the mean is pulled toward the
long tail, making it unrepresentative of the typical value. The median,
on the other hand, is the middle value and is not affected by extreme
scores. In healthcare cost data, which are often right-skewed, the
median is preferred because it provides a better indicator of central
tendency for the typical patient.
QUESTION 3
A public health official reports that the incidence rate of a disease is 25
per 100,000 person-years. This means:
A) 25 people have the disease at a specific point in time.
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B) 25 new cases of the disease occurred per 100,000 individuals in one
year.
C) 25 people out of 100,000 died from the disease.
D) The prevalence of the disease is 25%.
Answer: B) 25 new cases of the disease occurred per 100,000 individuals
in one year.
Explanation: Incidence rate measures the number of new cases that
occur in a population at risk over a specific time period. It is expressed
as new cases per population size per unit of time, often person-years.
Prevalence, by contrast, measures existing cases at a point in time.
QUESTION 4
In a normal distribution, what percentage of data falls within two
standard deviations above and below the mean?
A) 68%
B) 95%
C) 99.7%
D) 50%
Answer: B) 95%
Explanation: The empirical rule states that in a normal distribution,
approximately 68% of observations fall within ±1 standard deviation,
95% within ±2 standard deviations, and 99.7% within ±3 standard
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deviations. This is a fundamental concept in probability and inferential
statistics.
QUESTION 5
Which of the following is a type of probability sampling?
A) Convenience sampling
B) Quota sampling
C) Simple random sampling
D) Purposive sampling
Answer: C) Simple random sampling
Explanation: Probability sampling involves random selection, allowing
for statistical inferences about the population. Simple random sampling
is a method where every member of the population has an equal chance
of being selected. The other options are non-probability sampling
methods, which do not provide a basis for generalizing results to a
larger population.
QUESTION 6
A study reports a p-value of 0.03 for a hypothesis test. At a significance
level of 0.05, what is the correct conclusion?
A) Fail to reject the null hypothesis.
B) Reject the null hypothesis.
C) Accept the alternative hypothesis with certainty.