A.1.12.3 Investigating Variability

Begin with the data: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 Clear the data from the spreadsheet again and use technology to find the mean, standard deviation, median, and interquartile range. Enter the values here:

How do the standard deviation and mean change when you remove the greatest value from the data set?

How do the standard deviation and mean change when you add a value to the original set that is twice the greatest value?

What do you predict will happen to the standard deviation and mean when you remove the least value from the original data set? Check to see if your prediction was correct.

What happens to the standard deviation and mean change when you add a value to the original set that is equal to the mean? Add a second value equal to the mean. What happens?

Add, change, or remove values from the original data set to answer the question: What appears to change more easily, the standard deviation or teh interquartiel range? Explain your reasoning.