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CHS Statistics
MINITAB Assignment
School Suspensions Data Analysis
Find the data table online labeled, School Suspensions Data. This data table shows the number of
suspensions and the number of students enrolled in 41 local school districts in southwestern
Pennsylvania and eastern North Carolina during the 2011-2012 school year. At the α = .05 level of
significance, can you conclude that there is a difference in the average suspension rates between
schools in southwestern Pennsylvania and eastern North Carolina? Use MINITAB to summarize all of
your data. Type or paste your responses in a different color to this document, and submit only this
document through Moodle.
You will be scored on the accuracy of your values, as well as the detail of the entire process (including
the hypotheses, proper t-test, conclusions, and interpretation of conclusions to answer the question).
Round sample means to four decimal places. Show your work in the space below when applicable.
1. Copy and paste the column for the number of suspensions for PA into C1 of MINITAB. No work
needs to be shown on this document.
2. Copy and paste the column for enrollment for PA into C2 of MINITAB. No work needs to be
shown on this document.
3. Copy and paste the column for the number of suspensions for NC into C5 of MINITAB. No work
needs to be shown on this document.
4. Copy and paste the column for enrollment for NC into C6 of MINITAB. No work needs to be
shown on this document.
5. Find the proportions of suspensions for each of the 41 schools for PA (No work needs to be
shown on this document):
a. In MINITAB, go to Calc.
b. Go to calculator.
c. Store results in variable: C3
d. Expression: C1/C2 (Note that you will have to double click on C1 and C2)
e. Press OK.
6. Find the proportions of suspensions for each of the 41 schools for NC (No work needs to be
shows on this document):
a. In MINITAB, go to Calc.
b. Go to calculator.
c. Store results in variable: C7
d. Expression: C5/C6 (Note that you will have to double click on C5 and C6)
e. Press OK.
7. Conduct a two sample t-test to see if you can conclude that there is a difference in the average
suspension rates between schools in southwestern Pennsylvania and eastern North Carolina.
Note that 𝜇𝑃𝐴 = the mean percentage of suspensions in schools in southwestern PA, and 𝜇𝑁𝐶 =
the mean percentage of suspensions in schools in eastern North Carolina.
a. Notice that I asked you to conduct a two-sample t-test of the mean proportions of
suspensions for the defined areas. Why do you think it is appropriate to conduct this
type of test rather than a two-proportion z-test? (The two-sample t-test is the correct
way to analyze these data, and I want you to think about the reason).
b. Set up your hypotheses in words and symbols.
c. What is the average percentage of suspensions in southwestern PA? Go to STAT  Basic
Statistics  Display Descriptive Statistics and double click on C3.
d. What is the average percentage of suspensions in eastern NC? Go to STAT  Basic
Statistics  Display Descriptive Statistics and double click on C7.
e. Check the conditions for the hypothesis test. Don’t forget to show the histograms of
each distribution. Use the equation editor to input the appropriate symbols.
f.
Test the claim. Go to STAT  Basic Statistics  2-Samp t. Click the radio button next to
“Samples in different columns.” Define your first and second samples by double clicking
on C3 and C7 respectively. Click OPTIONS and only adjust your alternative if needed.
Press OK and OK. Copy and paste your results.
g. What is your conclusion?