1) The mean and the median are two types of measures of center. For some variables, the median might be a better measure of central tendency than the mean because the mean might misrepresent the variable.
Give a real-world example of when the median is preferred over the mean. In your example,
Specify what the variable is, and
Explain the advantage of using the median and the disadvantage of using the mean. (How might the mean misrepresent the variable? What might be real-world consequences of this misrepresentation?)
Refer to the eText and resources in the course Materials folder.
2) In addition to measuring the center of a distribution, it helps to measure its spread. The activity below provides practice for computing the sample variance and sample standard deviation using Excel.
Create your number collection, any 7-12 numbers of your choice.
Arrange them in order and find Median and Mean.
Calculate Sample Variance and Standard Deviation for your sample
To find Variance and Standard Deviation in Excel: Open a spreadsheet and enter data in the first column. Let’s say the data: 3,6,8,12,16,17,20,23,24 are entered in cells A1 to A9.
Go to Formulas at top ribbon, More Functions, Statistical, Scroll to var.s for sample variance. In No.1 dialog box enter cell range A1:A9. Note the variance value appears in bottom right of dialog box. (56.75)
Repeat to find standard deviation. Scroll to stdev.s for sample standard deviation. (7.533).
You can also find the mean and the median using Excel with the functions average(A1:A9) and median(A1:A9). If you are typing directly into a cell, remember to start the formula with an = sign.
Sample Solution
