Exploring Conditional Probability Concepts

Mr. Small explains the difference between regular and conditional probability using a two-way table. He demonstrates how to fill in the table with totals and calculate probabilities. Regular probability is calculated by dividing the number of favorable outcomes by the total number of outcomes. Conditional probability is determined by focusing on a subset of data, given a specific condition. Examples are provided to illustrate both types of probability calculations.

What are the two types of categories discussed in the two-way table?

• Students who are in the band and students who are not

• Students who are on the student council and students who are not

• Students who play sports and students who don't

• Students who take the bus and students who walk

What is the subtotal of students not on the student council?

• 30

• 240

• 170

• 200

What is the total number of students in the survey?

• 200

• 240

• 40

• 204

What is the total number of students who eat at the cafeteria?

• 204

• 36

• 40

• 30

What is the grand total of students in the two-way table?

• 200

• 40

• 240

• 204

How do you find the probability that a student is on the student council?

• Divide the number of students on the student council by the total number of students

• Multiply the number of students on the student council by the total number of students

• Subtract the number of students on the student council from the total number of students

• Add the number of students on the student council to the total number of students

What is the probability that a student is on the student council and eats at the cafeteria?

• 6/200

• 6/240

• 36/240

• 40/240

How do you calculate the probability of an intersection of two events?

• Multiply the probabilities of the two events

• Divide the number of occurrences of both events by the total number of students

• Add the probabilities of the two events

• Subtract the probabilities of the two events

What does conditional probability ask?

• The probability of an event happening without any conditions

• The probability of an event happening twice

• The probability of an event given that you already know something first

• The probability of an event happening in the future

What is the probability that a student eats in the cafeteria given that they are on the student council?

• 36/40

• 6/200

• 6/240

• 6/40