Calculating Probabilities Using the Addition Rule

This video tutorial teaches how to calculate probabilities using the addition rule. It begins with an introduction to the rule, followed by solving example problems, including a word problem about cat coat patterns. The lesson revisits an initial example involving flower colors to reinforce the concept. By working backwards, students learn to find the probability of intersections using given probabilities.

What is the probability of picking a plant that is both red and yellow if the probability of picking a red or yellow plant is 0.82, red is 0.64, and yellow is 0.48?

• 0.28

• 0.34

• 0.18

• 0.30

Using the addition rule, how do you calculate the probability of A or B?

• Add the probabilities of A and B, then subtract the probability of their intersection

• Multiply the probabilities of A and B

• Add the probabilities of A and B

• Subtract the probability of A from B

If the probability of A or B is 0.68, A is 0.31, and A and B is 0.27, what is the probability of B?

• 0.64

• 0.58

• 0.54

• 0.60

What is the first step in solving a probability problem using the addition rule?

• Guess the probability

• Substitute known values into the addition rule

• Subtract the smallest probability from the largest

• Multiply all given probabilities

In a sample of cats, 32% are striped, 41% are either spotted or striped, and 7% are both. What is the probability of a cat having spots?

• 0.12

• 0.14

• 0.16

• 0.18