1. Guide to Using Excel 2007 For Basic Statistical Applications
To Accompany
Business Statistics: A Decision Making Approach, 8th Ed.
Chapter 6:
Introduction to Continuous Probability Distributions By
Groebner, Shannon, Fry, & Smith
Prentice-Hall Publishing Company
Copyright, 2011

2. Chapter 6 Excel Examples
Using the Normal Distribution State Bank and Trust
Exponential Distribution– Haines Internet Service
Creating a Standard Normal Table

3. Standard Normal Distribution- State Bank and Trust
Issue: State bank managers have studied the time customers spend at the bank on business. They plan to offer a gift certificate to any customer who is required to spend over 30 minutes on bank business.
Objective: Use Excel 2007 to create a histogram and determine the probability that a gift certificate will be given to any customer. The data file is State Bank.xls.

4. Standard Normal – State Bank and Trust
Open file StateBank.xls

5. Standard Normal – State Bank and Trust
Using the Data Analysis – Histogram Function, Build the Histogram as indicated. Select Chart Output

6. Standard Normal – State Bank and Trust
Format as per Chapter 2

7. Standard Normal – State Bank and Trust
Using the Chart Tools option, Format the histogram, insert titles and labels
Next, determine probability of a service time exceeding 30 minutes.

8. Standard Normal – State Bank and Trust
Using the Chart Tools option, Format the histogram, insert titles and labels
Next, determine probability of a service time exceeding 30 minutes.

9. Standard Normal – State Bank and Trust
Select Formulas
Select Statistical
Select NormDist
Select Formulas
Statistical

10. Standard Normal – State Bank and Trust
Insert:
X = 30
Mean = 22.14
Standard Dev = 6.09
Cumulative – true
Probability P(X <= 30) = .9016

11. Exponential Distribution- Haines Internet Services
Issue: Assume the time between connect attempts averages two minutes and the distribution of time between attempts is assumed to be exponential.
Objective: Use Excel 2007 to compute the probability that that the time between connect attempts will be less than 45 seconds (.75 minutes).

12. Exponential Distribution - Haines Internet Services
Select the Formulas tab
Select More Functions
Select Statistical
Select EXPONDIST

13. Exponential Distribution - Haines Internet Services
Input:
X = .75
Lambda = .50
True
Cumulative Exponential Probability

14. Creating A Standard Normal Distribution Table
Issue: The Standard Normal tables in the Appendix of this text were created using Excel.
Objective: Use Excel to generate a standard normal table for z values below zero.

15. Creating the Standard Normal Table
Z-value, second decimal place
Z-value integer and first decimal place

16. Creating the Standard Normal Table
Formula:
ABS function is for absolute value.
Mean for NORMDIST function is = - .01
Notice use of absolute cell references to allow formula to be copied across and down to finish the table
Probabilities correspond to area on the standard normal table between the Z value and the mean = 0