Pettit 9-2 Notes D7 : Compute probabilities using tree diagrams 9-2 Tree Diagrams (pgs 374-377) D7 : Compute probabilities using tree diagrams

There are 4 different outcomes for the colors and sizes of the watch. Example 1 A certain type of watch comes in brown or black and in a small or large size. Find the number of color-size combinations that are possible. Make a tree diagram to show the sample space. Then give the total number of outcomes. Sample Space Size Color small brown, small brown large brown, large small black, small black large black, large There are 4 different outcomes for the colors and sizes of the watch.

Example 2 Suppose Pablo tosses 3 coins. Find the probability of all three coins landing on tails. Make a tree diagram to show the sample space. Then give the total number of outcomes, and the probability of all three landing on tails. Sample Space Coin #3 Coin #2 Coin #1 heads heads, heads, heads heads tails heads, heads, tails heads heads heads, tails, heads tails tails heads, tails, tails heads tails, heads, heads heads tails tails tails, heads, tails tails heads tails, tails, heads tails tails, tails, tails There are 8 different outcomes for the coin toss. The probability of all three coins landing on heads is .

You try… A family has two children. Draw a tree diagram to show the sample space of the children’s genders. Then determine the probability of the family having two girls.