Measures of Variability and Central Tendency
Imagine you have collected information on a health-related variable for 12 study participants. For this discussion, come up with 12 different data points pertaining to one continuous variable and enter them into the first column in an Excel spreadsheet. Examples of potential variables include: age, temperature, body weight, height, systolic blood pressure, number of minutes spent exercising/day, number of miles walked, etc. 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 identifying your variable, its unit of measurement (e.g. years for age, pounds for body weight) and report your results for each of the previously listed 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?
This exercise requires the use of the “Analysis ToolPak” within Excel. This feature is already part of the 2007 and 2010 Excel programs; 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
2. In the
Manage box, select
Excel Add-ins and then click
3. In the
Add-Ins available box, select the
Analysis ToolPak check box, and then click
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.