Assignment:
Sometimes a data set contains values that make no sense. What would you think if you found a height of 5?
An extremely high or low value may indicate an error in data entry. A height of 5 probably means 5 feet. The entries should all be in inches (5'=60").
An age of 100 years might be an outlier but not necessarily; an age of 222 (yes, that happened once) is probably an error. What should you do?
You may need to exercise some judgement in that case. I chose to delete the entry. Someone else might look at the other values and decide they belonged to a person who was 22 years old. If you change or delete values, include a list of the changes on the worksheet holding your data.
Discuss the 4 problems below. Be sure to use built-in spreadsheet functions wherever possible. Your observations are explanations are as important as the calculations!
Your job in each case is to use the most appropriate tool(s) to express the story held within the data. Use statistical vocabulary in your discussion.
If the Data Analysis Toolpak will be helpful, DAT will appear next to the problem.
The appropriate Excel functions are show for each problem. This will occur only the first time a function is used in the course.
Q1: Show the distribution of heights visually. Can you draw any conclusions? What does it mean to "show the distribution...visually?" What specific tool in Chapter 1 gives a picture of the data distribution?
Q2: Describe the distribution of weights with the Five Number Summary. Can you draw any conclusions? Hint: Use Excel functions for each part of the 5 number summary, not the Descriptive Statistics command under the Data Analysis Toolpak. Useful Excel functions: =Maximum, =Quartile, =Median, =Minimum
Q3: Find the mean, standard deviation and median for the age of our students. Represent the ages visually, using a stemplot, boxplot or histogram. Can you draw any conclusions? (25 points) Useful Excel functions: =Mean, =StandardDeviation,=Median
Q4: Ask one question about the data that we have not asked. Answer your question using the 4 step process : state; formulate; solve conclude. You must use numeric, visual and verbal analysis: calculate; show; and tell.