PS296 Lecture Notes - Lecture 5: Mutual Exclusivity, Conditional Probability
Basic Laws of Probability
Additive Law of Probability:
-given a set of mutually exclusive events, the probability of one event or another event is equal
to the sum of their separate probabilities
-the probability of drawing a blue or red marble from a jar of 100 marbles
-p(blue, red) = p(blue) + p(red)
If the probabiltiies that Marc C, Carly, and Rosa will be chosen as the PS296 class representative
are
.50, .30, and .20 respectively, what is the probability that either Marc C or Rosa will be chosen?
p(Mark, Carly) = p(.50) + p(.20)
P(Mark, Carly) = .70
-probability that Mark or Rosa will be chosen is .70
Smarties experiment:
7 yellow = 0.16
8 pink = 0.19
6 brown = 0.13
8 red = 0.19
5 green = 0.11