Tax Examination

Author David Graser, Yavapai College, Prescott, AZ (


This project helps students to examine how the likelihood of having a tax return examined is influenced by whether the taxpayer requests a refund or not. This is one of the last projects I use in Finite Math so students are expected to attack the problem with a limited number of scaffolding resources.

  • Content Area – Conditional probability, Baye’s Rule
  • Time Frame – 2 to 3 weeks with mini-lectures
  • Published – November 3, 2010
  • Keywords – probability, conditional probability, Baye’s Rule

Project Content

Project Letter (DOC | PDF)

Scaffolding Resources

Handout: Baye’s Theorem Example (DOC | PDF)
Handout: Baye’s Rule and Medical Testing (DOC | PDF)


  • The intent of this problem is to have students compute P(examined | refund) using Baye’s Rule.
  • Interpreting which probabilities the numbers correspond to is the most challenging aspect of this project.
  • This problem may also be solved using a contingency table.