Log onto website whereyou can observe your service bill for the last 12 months (electricbill, cell phone bill, water bill, etc.). If you do NOT feelcomfortable sharing this data, you can make up values.
- In excel, list the values of your bill for the last 12 monthson one column.
- Find the sample mean and sample standard deviation of yourdata.
- Pick three bills from the last 12 months and change the valuesinto z-scores. What does the z-score tell you about that particularmonth?
Analysis
- Between what two values would be considered a normal bill?Remember, being within 2 Standard Deviations is considerednormal.
- Are any of your bills in the last 12 months unusual? Veryunusual?
- Are there times when you would accept an "unusual" bill?Explain.
