Hi everyone! Read through the material below, watch the videos, work on the Excel lecture and follow up with your instructor if you have questions.


Learning Outcomes.

  • Determine if the data supports a hypothesis at a given significance level using known distributions.

Topic. This lesson covers: Chi-Squared Test for Independence – Contingency Table

  • Openstax Introductory Statistics
  • Introductory Statistics by Sheldon Ross, 3rd edition: Section 13.3
  • Statistics with Microsoft Excel by Beverly J. Dretzke, 5th ed., CHIDIST(x,df), CHIINV(p,df) P. 249 – 255

WeBWorK. Set 11.3



Chi-Squared Test for Independence with Contingency Table

The Applied View

Watch the video Inference for Two-Way Tables.

  1. What type of research is the host of this series, Dr. Pardis Sabeti, involved in?
  2. Dr. Sabeti’s work is modeled off of work done on malaria. What genetic mutation is an important source of resistance to malaria?
  3. What were the null and alternative hypotheses for testing whether the sickle cell gene protects against malaria?
  4. What is the rule for calculating the expected counts under the null hypothesis?
  5. The p-value of the chi-square test statistic turned out to be approximately 0. What can you conclude based on this p-value?

Exit Ticket

The following contingency table presents data from a sample of a population that is characterized in two different ways:

Image with Data

  • Determine the value of the test statistic when testing that the two characteristics are independent.
  • Would the null hypothesis be rejected at the 5 percent level of significance?
  • What about at the 1 percent level?