Lesson 17 Ratios Rates and Percents Experimental Probability

Lesson 17 Ratios, Rates and Percents Experimental Probability

Warm-Up Determine whether each probability is impossible, unlikely, equally likely, likely or certain. 1. You roll a 6 on a number cube. 2. There is a 0. 8 chance of rain today. 3. You close your eyes or blink your eyes at least once in the next five minutes. 4. There is a 0. 4 chance that the temperature will be greater than 60 degrees today. Write this probability as a percent and a simplified fraction.

Experimental Probability Target: Find and interpret the experimental probability of an event.

Vocabulary � Outcome: � Sample � Trial: One possible result from an experiment or probability event. Space: The set of all possible outcomes for an event. A single act of performing an experiment. � Experimental Probability: The ratio of the number of times an event occurs to the total number of trials.

Example 1 Abram had 2 red marbles and 1 white marble in a bag. He chose the white marble. Identify the outcome and show the sample space for this experiment. � Abram chose a white marble. ◦ Outcome: white � The possible marbles Abram could have chosen are red, red or white. ◦ Sample Space: {red, white}

Experimental Probability

Example 2 a Nik took a jelly bean out of a bag without looking. He recorded the color. He placed it back in the bag. He did this several times. The results are shown in the table. Color Red Yellow White Green Frequency 4 12 8 24 Find the total number of trials. � 4 + 12 + 8 + 24 = 48 trials

Example 2 b Nik took a jelly bean out of a bag without looking. He recorded the color. He placed it back in the bag. He did this several times. The results are shown in the table. Color Red Yellow White Green Frequency 4 12 8 24 Find the experimental probability his next jelly bean will be red. �

Example 2 c Nik took a jelly bean out of a bag without looking. He recorded the color. He placed it back in the bag. He did this several times. The results are shown in the table. Color Red Yellow White Green Frequency 4 12 8 24 Find the experimental probability his next jelly bean will be green. �

Exit Problems 1. Identify the sample space: Tom rolls a regular sixsided number cube. 2. Sherlock put his music player on random play. It chose the same song 3 out of the last 12 times it played a song. What is the experimental probability it will play the same song for its next selection? 3. Charlie made 4 out of 5 free throws at basketball practice today. What is the experimental probability he will make a free throw at the game tonight?

Communication Prompt Suppose you entered a contest where you will throw bean bags through a hole in a piece of plywood as part of a fundraiser. On the day of the contest, you will throw the bean bag 100 times. Explain how you could create an experiment to predict how many tosses you will make without actually throwing the bean bag 100 times. Identify your outcomes, sample space, and number of trials.