Appendix 2.4
Numerical Descriptive Statistics Using MegaStat
1
Appendix 2.4 ■ Numerical Descriptive Statistics Using MegaStat
The instructions in this section begin by describing the entry of data into an Excel worksheet. Alternatively, the
data may be downloaded from this book’s website. Please refer to Appendix 1.1 for further information about
entering data, saving data, and printing results in Excel. Please refer to Appendix 1.2 for more information about
using MegaStat.
To analyze the gas mileage data:
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Enter the mileage data into column A with the
label Mpg in cell A1 and with the 50 gas mileages
in cells A2 through A51.
In order to compute descriptive statistics:
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Select Add-Ins : MegaStat : Descriptive Statistics
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Place checkmarks in the checkboxes that
correspond to the desired statistics. If tolerance
intervals based on the empirical rule are desired,
check the “Empirical Rule” checkbox.
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Click OK in the “Descriptive Statistics” dialog box.
In the “Descriptive Statistics” dialog box, use the
autoexpand feature to enter the range A1:A51
into the Input Range box.
The output will be placed in an Output
worksheet.
To construct a boxplot of satisfaction ratings:
•
Enter the satisfaction rating data into column A
with the label Ratings in cell A1 and with the 20
satisfaction ratings in cells A2 to A21.
•
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Select Add-Ins : MegaStat : Descriptive Statistics
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Place a checkmark in the Boxplot checkbox.
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Move the boxplot to a chart sheet and edit as
desired.
In the “Descriptive Statistics” dialog box, use the
autoexpand feature to enter the input range
A1:A21 into the Input Range box.
Click OK in the “Descriptive Statistics” dialog box.
The boxplot output will be placed in an output
worksheet.
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Chapter 2
Descriptive Statistics
Least squares line and correlation for the sales
volume data:
To compute the equation of the least squares line:
•
Enter the advertising and sales data into
columns A and B—advertising expenditures in
column A with label “Ad Exp” and sales values
in column B with label “Sales Vol”.
•
Select Add-Ins : MegaStat : Correlation /
Regression : Scatterplot
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In the Scatterplot dialog box, use the autoexpand feature to enter the range of the values of
advertising expenditure (x), A1:A11, into the
“horizontal axis” window.
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Enter the range of the values of sales volume
(y), B1:B11, into the “vertical axis” window.
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Place a checkmark in the “Plot linear regression
line” checkbox.
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Select Markers as the Display option.
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Move the scatterplot to a chart sheet and edit
the plot as desired.
Click OK in the Scatterplot dialog box.
The equation of the least squares line is
displayed in the scatterplot.
To compute the sample correlation coefficient between
sales volume (y) and advertising expenditure (x):
•
Select Add-Ins : MegaStat : Correlation /
Regression : Correlation Matrix
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In the Correlation Matrix dialog box, use the
mouse to select the range of the data A1:B11 into
the Input window.
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Click OK in the Correlation Matrix dialog box.
The sample correlation coefficient between
advertising expenditure and sales volume is
displayed in an output sheet.