Probability

Probability = (desired outcome)                   Ex.   P(heads)= 1/2 = 50% = .5
                   ( total # of outcomes)


The types of probability:
1. Theoretical- what the results should look like in theory.
 Ex. flipping a coin and getting heads is 1/2 or 50%


2. Experimental- The results are found out in tests.
Ex. flipping a coin 100 times and getting heads 56 times


This type of probability isn't accurate if very few trials are done.


Tree diagrams:
The outcomes for 2 probabilities; flipping a coin and rolling a die.


or it can be written in a table called a sample space


Sample space
H-1       T-1
H-2       T-2
H-3       T-3
H-4       T-4
H-5       T-5
H-6       H-6

To find the probability of 2 events occurring at the same time you multiply both the probabilities together.


Ex. Probability of getting heads is 1/2 and rolling a 5 is 1/6 so 1/2 x 1/6 = 1/12