1. Objective  Find the experimental probability that an event will occur.

2. Glossary Terms Probability – the likelihood that an event will occur experimental probability – finding probability by a series of trials favorable outcome – the outcome that is desired in a probability experiment Trial – the simulation of one event in an experiment

3. Rules and Properties Experimental Probability The experimental probability of an event, P(E), is given by: P(E) = number of favorable outcomes total number of trials

4. Two number cubes were rolled 100 times. An even number appeared as a sum 47 times. Based on this experiment, what is the experimental probability that two rolled number cubes will show a sum that is an even number? There were 100 trials and 47 successful outcomes. probability = number of favorable outcomes total number of trials = 47. 100 = 0.47= 47% So there is a 47% probability that the number cubes will come up with an even sum.

5. Two coins were tossed 200 times. Two heads appeared 48 times. Based on this experiment, what is the experimental probability that two flipped coins will show two heads.  There were 200 trials and 48 favorable outcomes. 48. 200 = 0.24 = 24% Based on this experiment, there is a 24% probability that two flipped coins will show two heads.

6. Key Skills Problem: Two number cubes were rolled 100 times. Find the experimental probability of an event. Solution: There were 100 trials and 30 successful outcomes. 30 100 P(sum less than 6) = = 30% A sum less than 6 appeared 30 times. Find the experimental probability in this case of rolling a sum less than 6.

7. Key Skills Problem: Two coins were tossed 150 times. Find the experimental probability of an event. Solution: There were 150 trials and 66 successful outcomes. 66 150 P(two heads) = = 44% Two heads appeared 66 times. Find the experimental probability that two flipped coins will show two heads. TOC