Checkpoint: Conditional Probability Solutions

Find the probability that:

$P (Muffin) = 0.4 P (Coffee) = 0.1333 P (Coffee and Muffin) = 0.0267$

$P (M | C) = \frac{P (M and C)}{P (C)} = \frac{0.0267}{0.1333} = 0.2003$

$P (C | M) = \frac{P (M and C)}{P (M)} = \frac{0.0267}{0.4} = 0.0668$

Note

Q: What are the key words that indicate you are finding a conditional probability?

A: if, when, after, given that

Q: How can you check if the events are independent?

A: Multiply individual probabilities together. If $P (A and B) = P (A) \cdot P (B),$ then they are independent.