Education Technology

Statistics: Conditional Probability
by Texas Instruments


  • Students will identify the difference between the probability of an outcome and the conditional probability of an outcome.
  • Students will answer probability questions using information presented in a table and in a graph.


  • conditional probability
  • probability
  • two-way table

About the Lesson

This lesson involves thinking about probability when additional information is given.
As a result, students will:

  • Investigate probability questions using tabular and graphical information.
  • Explain why a two-way table with two rows and two columns with fixed row and column totals needs only one input to determine the others.
  • Answer questions about the probability of an outcome using data from a two-way table.
  • Use bar graphs separated according to categories to answer probabilities and connect these graphs to information of the form P(A|B).
  • Choose between information presented as the probability of A given B and the probability of B given A (A|B and B|A) to answer specific probability questions.