IT 223

Fall 2026

Craig Miller

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Weekly Notes

• Week 0
• Week 1
• Week 2
• Week 3
• Week 4

Assignments

• Assignment 1
• Assignment 2
• Assignment 3
• Assignment 4

Technical References

• Course text (OpenStax Statistics)
• OpenIntro Statistics
• R tutorial

Assignment 2
Data Distributions
Submit before 11:30 Sunday September 27

Overview

For this assignment, you will practice interpreting distributions and applying your knowledge to draw inferences from them.

Practice tasks

1. Download the rolls folder and run the rolls.R script. You will see that the data frame has a set1 column and a set2 column. For each of the set1 and set2 vectors, do the following:
   1. Summarize the descriptive statistics
   2. Create a boxplot and a histogram. Describe their distributions.
   3. How many values are within one standard deviation of the mean? Is this consistent with the empirical rule?
   4. How many values are within two standard deviations of the mean? Is this consistent with the empirical rule?
2. For the rolls set (above question), one set was created by simulating one 16-sided die (labeled 0 through 15) and another set was created by simulating the sum of 3 6-sided dice (labeled 0 through 5). Which set do you think was created by the single-simulation and which was created by the 3-dice simulation? Why? Support your answer.
3. For each of your web server response time samples of last year, do the following:
   1. Report (again) the mean and standard deviation.
   2. How many values are within one standard deviation of the mean? Is this consistent with the empirical rule?

Deliverable

Create word or pdf file that contains the following:

1. A summary statement of your experience completing this assignment. It should contain a major finding from the paragraph of the last task (not the whole paragraph). Place this summary statement at the top of your document.
2. Your clearly labeled answers to questions and problems
3. Any additional details or output that you would like to include or document but are too long to insert among your answers.

Grading

The assignment is worth 5 points. Full credit will be awarded to complete, accurate and well presented submissions. Points will be deducted for the following:

• Summary statements that do not reference concepts or details specific to the assignment
• Summary statements without meaningful experiences and explanations
• Incomplete answers
• Inaccuracies (possibly excepting minor ones)