1. Chapter 1.6 Probability Objective: Students set up probability equations appropriately

2. Experimental Probability • Probability of event = • Number of times event occurs Number of trials

3. Example 1 • A player hit the bull’s eye on a circular dartboard 8 times out of 50. Find the experimental probability that the player hits the bull’s eye.

4. Number of times event occurs = Number of trials We need to use the formula.

5. Example 2 • Find the theoretical probability of rolling a multiple of 3 with a number cube? How about rolling an odd? • The Cube is a normal six sided di.

6. A) How many numbers on the cube are a multiple of 3? • Yes 2 numbers, 3 and 6. • So we get… 2 = 1 6 3 • B) How many numbers are odd? • Yes 3 numbers, 1,3,5 So we get… 3 = 1 6 2

7. Experimental Probability Example 3 • Suppose that all the points on the circular dartboard shown below are equally likely to be hit by a dart you have thrown. Find the probability of only scoring 2 points with one throw. • Note: The radius of each circle is one unit larger than the one below it. 20 20 10 5 2

8. First we need to find the area of the whole dart board. This is the denominator because any throw can hit any where on the dart board. • To find the area of the green we need to subtract the areas of the others. So we get (using area πr2 of a circle) • π(4r)2 – π(3r)2 π(4r)2 =16πr2 - 9πr2 16πr2 = 7πr2 16πr2 20 20 10 5 2

9. P. 42 (1- 19) odd • Omit 3 and 5