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 Goodness of Fit Test Woodtrim Products  Contingency Analysis 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

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 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 p- value 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. Goodness of Fit – Woodtrim Products

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 Use Excel to determine whether there is a statistically significant relationship between absenteeism and marital status. Data file is Benton.xls

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. Contingency Analysis – Benton Industries