CALIFORNIA STATE UNIVERSITY

CALIFORNIA STATE UNIVERSITY, HAYWARD
STATISTICS DEPARTMENT

Statistics 6011 Statistical Modeling for Management and Economics

Handout 1: Data Analysis with Minitab

Minitab is a statistics program used to analyze data. It has many built in statistical routines that can be used to analyze data you input into a Minitab Worksheet. Most of its statistics commands are under menu heading Stat. Also, under the menu heading Graph many graphical routines are available to graph data.

Pulse Rate Analysis: Here we will analyze a set of pulse rate data. We begin by inputting a set of data. Next, we graph the data using a histogram, stemplot, and boxplot. Lastly, we will calculate some descriptive statistics such as the mean, median, and standard deviation.

Input Data into a Minitab Worksheet: To input data type each value into a cell down the first column. In Minitab values of a variable are input down a column. For this demonstration we will analyze the following data:

73	64	75	74	81
76	56	40	75	72
75	65	70	74	73
79	72	62	50	68
76	49	80	67	64

In the Worksheet window under C1 type Pulse. Now we enter the data in the cells in the first column C1. In the first cell enter 73, in the second cell enter 76, continue down the column until all 25 numbers are entered. To check that the data have been entered, in the Session window, type print c1. You should see

MTB > print c1

Data Display

Pulse
     73     64     75     74     81     76     56     40     75     72
     75     65     70     74     73     79     72     62     50     68
     76     49     80     67     64

MTB >

Graphs: We will now graph the data.
1. Histogram: To make a histogram go to Graph in the menu at the top, next select Histogram, double click on Pulse, and finally click OK. You should see a histogram on the screen. How would you describe this histogram? Symmetric or skewed?
2. Boxplot: For a boxplot go again to Graph in the menu, next select Boxplot, double click on Pulse, and finally click OK. You should see a boxplot appear. What does it look like?
3. Stemplot: To make a stemplot again select Graph, next select Character Graph at the very bottom, then select Stem-and-Leaf, double click on Pulse, and finally OK. You should see
```
MTB > Stem-and-Leaf 'Pulse'.

Character Stem-and-Leaf Display

Stem-and-leaf of Pulse     N  = 25 Leaf Unit = 1.0

    1    4 0
    2    4 9
    3    5 0
    4    5 6
    7    6 244
   10    6 578
   (7)   7 0223344
    8    7 555669
    2    8 01

MTB >
```
  What does this graph suggest about the data? Is it the same as the other graphs?
Numerical Descriptive Statistics: To calculate some descriptive statistics we use the describe command. To implement this command. Select the menu item Stat, next go to Basic Statistics, then click the first option Display Descriptive Statistics, double click on Pulse. You should see the following in the Session window:
```
MTB > Describe 'Pulse'.

Descriptive Statistics

Variable  N       Mean     Median     TrMean    StDev      SE Mean
Pulse    25      68.40      72.00      69.09    10.32      2.06

Variable       Minimum    Maximum         Q1         Q3
Pulse           40.00       81.00       64.00      75.00

MTB >
```