http://www.ck12.org Chapter 15. Concepts of Statistics
- After entering the data in a column, you can use the power of the embedded programming of the spreadsheet to
make a second column of just the average.- The average command is: “=average(A2:A11)”
You can subtract one cell from another cell to find the difference. You can then square the difference to find the
difference squared. You can then sum these values using the sum command.
- The sum command is: “= sum(D2:D11)”
Finally, just divide the sum by the number of observations (which is 10) to get the variance.
Practice
- What are the similarities and differences between standard deviation and variance?
- Data Set A has a mean of 30 and a standard deviation of 10. Data Set B also has a mean of 30, but a standard
deviation of 2. What does this mean about Data Set A compared to Data Set B?
Calculate the variance of each set of data by hand. - Sample: 1, 4, 7, 10, 3, 6, 12, 5, 8, 16, 21, 3, 1, 5
- Population: 23, 27, 19, 24, 20, 22, 31, 30, 28
- Sample: 64, 62, 60, 58, 54, 60, 61, 63, 47, 100, 29, 59
Calculate the variance of each set of data using your calculator. Compare your answers to your answers to 3-5. - Sample: 1, 4, 7, 10, 3, 6, 12, 5, 8, 16, 21, 3, 1, 5
- Population: 23, 27, 19, 24, 20, 22, 31, 30, 28
- Sample: 64, 62, 60, 58, 54, 60, 61, 63, 47, 100, 29, 59
- Ifσ^2 =16, what is the population standard deviation?
- Which data set has the largest standard deviation?
a. 10 10 10 10 10
b. 0 0 10 10 10
c. 0 9 10 11 20
d. 20 20 20 20 20