Name:___________________________
Date:____________________
Labouré College
Essentials of Statistics
MAT 3410
Chapter 7.4 through 7.5 Quiz Prep
Matthew Gitlin and colleagues followed a population of chronic dialysis patients to study
their patterns of getting blood transfusions and payments to Medicare.
Gitlin et al. found that, among their patients, Charlson Comorbidity Index was normally distributed, with:

μ = 4.3

ϭ = 2.5
Reference: Gitlin, M., Lee, J. A., Spiegel, D. M., Carson, J. L., Song, X., Custer, B. S., ... & Ashfaq, A.
(2012). Outpatient red blood cell transfusion payments among patients on chronic dialysis. BMC
nephrology, 13(1), 145.
Answer the questions below based on the parameters listed above from the Gitlin
article.
Round z-scores to 2 digits in your calculations, and look up the probability in the z-table.
Report the probability out to 4-digits past the decimal
Report whole percentage number.
Unless otherwise noted, round standard error to 1-digit past the decimal.
1.
What is the probability that 1 chronic dialysis patient will have a Charlson Score >
5 (1 point)?
2.
What is the probability that a sample of 9 chronic dialysis patients will have a
mean Charlson Score > 5 (1 point)?
3.
What is the probability that a sample of 25 chronic dialysis patients will have a
mean Charlson Score > 5 (1 point)?
4.
What is the probability that 1 chronic dialysis patient will have a Charlson Score
between 4 and 5? (2 points)?
5.
What is the probability that a sample of 9 chronic dialysis patients will have a
mean Charlson Score between 4 and 5? (2 points)?
6.
What is the probability that a sample of 25 chronic dialysis patients will have a
mean Charlson Score between 4 and 5? (2 points)?
Page 1
©Copyright Monika Maya Wahi 2015
7.
Why is it that the probability of getting a sample with a sample mean near the
population mean always increases as you sample more individuals?
a.
b.
c.
d.
Page 2
The bigger the standard deviation, the smaller the n.
The bigger the n, the smaller the standard error.
The bigger the mean, the smaller the variance.
The bigger the variance, the smaller the standard deviation.
©Copyright Monika Maya Wahi 2015