Measures of Variability and Central Tendency
For this discussion, come up with 20 different data points (set of data) and enter them into the first column in an Excel spreadsheet. The data points can be any numbers you want as long as there are 20 of them. Your set of data should reflect one of the following criteria:
- Create a set of data for which the mean is greater than the median.
- Create a set of data for which the mean and median are equal but are different from the mode.
You will then use the descriptive statistics option in Excel, which is explained in Chapter 1 of your course text. You should get an output similar to Figure 1.2. This output must contain the following values: mean, standard error, median, mode, standard deviation, sample variance, kurtosis, skewness, range, minimum, maximum, sum, count. Begin your discussion by reporting your results for each of these values. Based on this output, which single value best describes this set of data and why? If you could pick three of these values instead of only one, which three would you choose and why? It is important to note that the answers to these questions may be different for each of you since you are each using unique sets of data.
Guided Response: Review several of your classmates’ posts. Provide a substantive response to at least two of your peers. Do you agree with their selections of the best value based upon their data?
This exercise requires the use of the "Analysis ToolPak" within Excel. This feature is already part of the 2007 and 2010 Excel program; however, it must be activated. The following directions were provided by the "Help" function within Excel. If you experience issues while following these steps, utilize the "Help" function within Excel or contact Microsoft's technical support for Excel.
The Analysis ToolPak includes the tools described below. To access these tools, click Data Analysis in the Analysis group on the Data tab. If the Data Analysis command is not available, you need to load the Analysis ToolPak add-in program.
Load the Analysis ToolPak
1. Click the File tab, click Options, and then click the Add-Ins category.
2. In the Manage box, select Excel Add-ins and then click Go.
3. In the Add-Ins available box, select the Analysis ToolPak check box, and then click OK.
Tip: If Analysis ToolPak is not listed in the Add-Ins available box, click Browse to locate it. If you are prompted that the Analysis ToolPak is not currently installed on your computer, click Yes to install it.