Download Guide to Using Excel For Basic Statistical Applications

Guide to Using Excel For Basic
Statistical Applications
To Accompany
Business Statistics: A Decision Making
Approach, 6th Ed.
Chapter 12:
Goodness of Fit Tests and Contingency
Analysis
By
Groebner, Shannon, Fry, & Smith
Prentice-Hall Publishing Company
Copyright, 2005
Chapter 12 Excel
Examples
 Goodness
of Fit Test
Woodtrim Products
 Contingency Analysis
Benton Industries
Goodness of Fit Woodtrim Products
Issue:
The company has recently become concerned
that the ripsaw may not be cutting to the
manufacture’s specifications
Objective:
Use Excel to determine whether the data set’s
mean and standard deviation meet the manufacturer’s
specifications. Data file is Woodtrim.xls
Goodness of Fit – Woodtrim Products
Open File Woodtrim.xls
Goodness of Fit – Woodtrim Products
Label columns
and define
classes.
Goodness of Fit – Woodtrim Products
Use the
COUNTIF
function to find
the number of
data values less
than -.02.
Goodness of Fit – Woodtrim Products
Again use the
COUNTIF only this
time subtract the
observations in the
previous cell to find
the number of data
values in the current
cell.
Goodness of Fit – Woodtrim Products
Continue to use
COUNTIF while
subtracting the
observations in the
previous cell to find
the number of data
values in the current
cell.
Goodness of Fit – Woodtrim Products
Notice change
in the
COUNTIF
function for
the final cell.
Also, sum the
observations.
Goodness of Fit – Woodtrim Products
Use the
NORMDIST
function to
find the
expected
probability
of values less
than -.02
given the
expected
mean and
standard
deviation.
Goodness of Fit – Woodtrim Products
Continue to use
the NORMDIST
function to
generate
probabilities, but
to get discrete
values, subtract
out the sum of
the preceding
cells.
Goodness of Fit – Woodtrim Products
To find the
Expected
Frequencies
multiply the
Normal
Distribution
values by
300.
Goodness of Fit – Woodtrim Products
Compute the Chi square
value in column N using the
formula for each
combination of cells.
Goodness of Fit – Woodtrim Products
Summing the individual values
gives the Chi square value.
Goodness of Fit – Woodtrim Products
To find the pvalue click on the
Function button,
then select
Statistics and
CHITEST.
Goodness of Fit – Woodtrim Products
Enter the
ranges for
the Actual
and
Expected
frequencies.
Goodness of Fit – Woodtrim Products
The p-value is
determined.
Contingency Analysis Benton Industries
Issue:
The company was interested in determining
the relationship between absenteeism and marital
status.
Objective:
Use Excel to determine whether there is a
statistically significant relationship between
absenteeism and marital status. Data file is
Benton.xls
Contingency Analysis – Benton Industries
Open File Benton.xls
Contingency Analysis – Benton Industries
Use this
Formula to
find the
expected
number of
single people
with zero
absences.
Contingency Analysis – Benton Industries
Using similar
formulas
determine the
expected values
for all the
combinations of
absentee rate
and marital
status Shown in
green.
Contingency Analysis – Benton Industries
Use this formula to
determine the Chi Square
value.
Contingency Analysis – Benton Industries
To find the Chi Square critical
value, click on the function
button, then select Statistical
and CHIINV.
Contingency Analysis – Benton Industries
Enter the
appropriate
Probability
and Degrees
of Freedom to
find the
critical value.