LIR 832: MINITAB WORKSHOP

Transcription

1 LIR 832: MINITAB WORKSHOP Opening Minitab Minitab will be in the Start Menu under Net Apps. Opening the Data Go to the following web site: Right-click and Save Target As on the link for Company Sales (Save it to the desktop) In Minitab, select File Open Worksheet and find the file Company Sales. Learning the Variable Names This data set includes 79 observations on a number of characteristics of specific companies: Company: Company Name Assets: Amount of assets (in millions) Sales: Amount of sales (in millions) Market_Value: Market Value of the company (in millions) Profits: Profits (in millions) Cash_Flow: Cash Flow (in millions) Employees: Number of employees (in thousands) Sector: Type of market the company is associated with Basic Structure

2 Minitab saves all materials related to a session as a Project. This includes all graphs, datasets, results, commands, etc. Within this project is a worksheet, which is the raw data we use here. Variable Names: You can add or edit variable names by clicking on the names above the columns. Note that columns will either be labeled as text columns ( C1-T ) or numeric (C2). Statistical Commands Results appear here. Data here (the worksheet)

3 Adding Data: You can add data in a number of ways. You can either hand-enter data or you can make patterned data under the Calc Make Patterned Data Simple Set of Numbers (or other options)

4 Making Dummy (or Indicator) Variables Suppose you want to convert the Sector column into a series of 0/1 variables in order to include them in a regression equation (you can t just put the Sector variable in the equation since it is non-numerical). Go to Calc Make Indicator Variables

5 Variable to examine Where to put your new variable The variable Sector has 9 values. Thus, we must create nine dummy variables which needs nine empty columns. Thus, we input C9-C17 and we find the following : 9 New Variables One Dummy Variable for Each Sector

6 You can then label each column based on what it represents.

7 Descriptive Statistics We can quickly calculate the descriptive statistics for each numeric variable. Follow the following steps: Click on appropriate variables (note that text variables are not appearing).

8 After clicking on the Statistics tab, the following menu pops up, allowing you to select all the statistics you will need for your analysis: Upon hitting OK on your main selection menu, your results should look like : Descriptive Statistics: Assets, Sales, Market Value, Profits, Cash Flow,... Variable N N* Mean SE Mean StDev Minimum Q1 Median Q3 Assets Sales Market Value Profits Cash Flow Employees Variable Maximum Assets Sales Market Value Profits Cash Flow 9874 Employees

9 Descriptive Statistics By Category: You can also calculate descriptive statistics by subcategory. For example, if we want the descriptive statistics by Sector, we can do the following: Will give us descriptive statistics for each sector Descriptive Statistics: Assets, Sales, Market Value, Profits, Cash Flow,... Variable Sector N N* Mean SE Mean StDev Minimum Q1 Assets Communication * Energy Finance HiTech Manufacturing Medical Other Retail Transportation Sales Communication * Energy Finance HiTech Manufacturing Medical Other Retail Transportation

10 Market Value Communication * Energy Finance HiTech Manufacturing Medical Other Retail Transportation Profits Communication * Energy Finance HiTech Manufacturing Medical Other Retail Transportation Cash Flow Communication * Energy Finance HiTech Manufacturing Medical Other Retail Transportation Employees Communication * Energy Finance HiTech Manufacturing Medical Other Retail Transportation Variable Sector Median Q3 Maximum Assets Communication * Energy Finance HiTech Manufacturing Medical Other Retail Transportation Sales Communication 5821 * 9084 Energy Finance HiTech Manufacturing Medical Other Retail Transportation Market Value Communication 6264 * Energy

11 Finance HiTech Manufacturing Medical Other Retail Transportation Profits Communication 666 * 1093 Energy Finance HiTech Manufacturing Medical Other Retail Transportation Cash Flow Communication 1578 * 2577 Energy Finance HiTech Manufacturing Medical Other Retail Transportation Employees Communication 50.7 * 79.4 Energy Finance HiTech Manufacturing Medical Other Retail Transportation

12 Basic Graphing Minitab allows you to quickly and easily create graphs of different variables. If you look under the Graphs command, you ll find:

13 SCATTERPLOT: There are many options one can use with the scatterplot command, including asking Minitab to include the regression line. SIMPLE SCATTERPLOT OF PROFITS (Y) vs. EMPLOYEES (X):

14 7000 Scatterplot of Profits vs Employees Profits Employees OR, WITH ADDING THE WITH REGRESSION OPTION, WE D FIND:

15 7000 Scatterplot of Profits vs Employees Profits Employees

16 HISTOGRAM (OF EMPLOYEES ):

17 Histogram of Employees Normal 50 Mean StDev N Frequency Employees BOX-AND-WHISKER PLOT ( BOXPLOT ) OF ASSETS:

18 60000 Boxplot of Assets Assets

19 MULTIPLE BOX PLOTS ON SAME GRAPH:

20 60000 Boxplot of Assets, Sales Data Assets Sales EDITING TITLES: On your graph, right-click on the title Boxplot of Assets, Sales to change the title text, font, etc.

21 Now, change the title to Comparison of Company Sales vs. Company Assets, and make the title text 18-pt font, in Times New Roman, in the color red. Comparison of Company Sales vs. Company Assets Data Assets Sales Note: You can also change the X-axis and Y-axis labels in similar fashions.

22 LESSON CHECK EXERCISES With the techniques learned in this lesson, complete the following exercises: 1. Change the variable Name to read Company. 2. Calculate descriptive statistics for firms that are in the communication field and those that are not. 3. Create a histogram of sales. 4. Create a scatterplot of sales (y) vs. assets (x). 5. Now create a scatterplot with a regression line of sales (y) vs. assets (x). 6. Retitle this graph, and change all the labels and titles to be in blue font.