Guide to Using Excel 2007 For Basic Statistical Applications To Accompany Business Statistics: A Decision Making Approach, 8th Ed. Chapter 13: Goodness-of-Fit Tests and Contingency Analysis By Groebner, Shannon, Fry, & Smith Prentice-Hall Publishing Company Copyright, 2011

Chapter 13 Excel Examples Goodness of Fit Test Goodness of Fit Test Goodness of Fit Test Goodness of Fit Test Woodtrim Products Woodtrim Products Contingency Analysis Contingency Analysis Contingency Analysis Contingency Analysis Benton Stone and Tile

Goodness of Fit - Woodtrim Products Issue: The company has recently become concerned that the ripsaw may not be cutting to the manufacturer’s specifications Objective: Use Excel 2007 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 the file Woodtrim.xls

Goodness of Fit – Woodtrim Products Label Columns and identify classes

Goodness of Fit – Woodtrim Products Use the COUNTIF function to find the number of 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 Propagate the function down, changing: The second parameter of the COUNTIF function to reflect the top of the range Subtract the sum of the cells above the current cell from the results of the COUNTIF function

Goodness of Fit – Woodtrim Products Note the changed formula for the last cell Sum all the above cells for the total

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, remembering to subtract out the sum of the preceding cells.

Goodness of Fit – Woodtrim Products Expected Frequency = Normal Probability Distribution * 300

Goodness of Fit – Woodtrim Products Compute the Chi square values in column J using the formula in the header

Goodness of Fit – Woodtrim Products Summing the individual values give the Chi square value

Goodness of Fit – Woodtrim Products To find the p=value Select the Formulas Tab Select More Formulas Select Statistical Select CHITEST

Goodness of Fit – Woodtrim Products Actual Range – Observed – g2:g7 Expected Range – expected – I2:I7

Goodness of Fit – Woodtrim Products The p-value is determined

Contingency Analysis - Benton Stone and Tile Issue: The company was interested in determining the relationship between absenteeism and marital status. Objective: Use Excel 2007 to determine whether there is a statistically significant relationship between absenteeism and marital status. Data file is Benton.xls

Contingency Analysis – Benton Stone and Tile Open the file Benton.xls

Contingency Analysis – Benton Stone and Tile Use this formula to find the Expected number of Single People with Zero absences

Contingency Analysis – Benton Stone and Tile Copy this formula to calculate all the expected cell frequencies.

Contingency Analysis – Benton Stone and Tile

To find the Chi Square critical value: Select the function button Select category = All or Statistical Select CHIINV OK

Contingency Analysis – Benton Stone and Tile Probability =.05 Deg_freedom = 6 OK Critical Value =12.59