Cellular phone testing for Chi-Squared Goodness of Fit

In this activity, you will be using data obtained from a major manufacturer of cellular phones to perform a chi-squared goodness of fit test. The data consists of 10 values that are gathered while testing cellular phones during the manufacturing process. You will use the DIG Stats Online Chi-Squared Calculator to help you in this endeavor.

Cellular phones are becoming mainstream in today's society. Factories world-wide are producing thousands of phones each day to keep pace with the increasing demand. Manufacturers work hard to provide a technically superior product that is performance and feature rich. To assist in achieving performance guidelines, manufacturers perform exhaustive testing on their products to ensure peak performance.

As phones are tested, the data is collected and uploaded to a central server for further analysis. Phone performance statistics are monitored and stored for trend analysis and quality assurance.

This data exists in two files; one in Excel Data format and one in Text format. You'll need to use the DIG Stats Online Chi-Squared Calculator; to use it just download either format, open the calculator, and enter the data by hand. (The TI-83 does not have sufficient chi-square computation abilities to be used.)

What are your null and alternate hypotheses? What is the alpha level you're using? What is the c2 value for the data? Is the data independently distributed? What about the degrees of freedom?

Original work on this document was done by Central Virginia Governor's School student Ryan Nash (Class of '00).

Copyright © 1999 Central Virginia Governor's School for Science and Technology, Lynchburg, VA