On a loose leaf sheet of paper answer the following questions about the random samples.

Transcription

1 7.SP.5 Probability Bell Ringers On a loose leaf sheet of paper answer the following questions about the random samples. 1. Veterinary doctors marked 30 deer and released them. Later on, they counted 150 deer, 12 of which had marks. To the nearest whole number, what is the best estimate for the deer population? 2. Gregory collected two random samples of 100 Woman regarding woman s color bag preference for his new bag business. Make an inference from the data. 3. Herald is keeping track of eagles. To do so, he put tags on 25 eagles and released them. Later, he catches 120 eagles; 16 eagles were tagged. Find the best estimate for the Eagle population? 4. Joanna uses a random sample of 50 students in her grade and asks them about their favorite type of movies. She writes the data in the table shown. If there are a total of 500 students in her grade, what are two inferences you can make about the population?

2 Bell ringer review 1. Veterinary doctors marked 30 deer and released them. Later on, they counted 150 deer, 12 of which had marks. To the nearest whole number, what is the best estimate for the deer population? 12 = X 12x = x = x = 375 deer

3 Bell Ringer Review 2. Gregory collected two random samples of 100 Woman regarding woman s color bag preference for his new bag business. Make an inference from the data. The black bag is the most popular bag. The black bag is twice as popular as the blue and red bag. The blue and red bags are approximately half as popular as the black bag. The black bag is about half of the total votes.

4 Bell Ringer Review 3. Herald is keeping track of eagles. To do so, he put tags on 25 eagles and released them. Later, he catches 120 eagles; 16 eagles were tagged. Find the best estimate for the Eagle population? 16 = X 16x = x = x = eagles

5 Bell ringer Review 4. Joanna uses a random sample of 50 students in her grade and asks them about their favorite type of movies. She writes the data in the table shown. If there are a total of 500 students in her grade, what are two inferences you can make about the population? Favorite type of movie Action 10 Drama 26 Comedy 6 Fantasy 8 Number of Students The majority of the students prefer dramas. About ½ of the students prefer dramas About 4 times as many people prefer dramas than fantasys

6 7.SP.5 Probability Created By Melissa Forsyth

7 What is probability? What if I told you that we were going to play a game. I will choose three students and the first student I pick will pick their color first, and the second student can pick next, and the third student will the remaining color. The players will use the following spinner to play. Each person takes a turn spinning the spinner and recording what color the spinner stops on. The winner is the person whose color is the first to happen 10 times. Who is most likely to win the game? Green Why? It has the biggest piece.

8 What if we changed the spinner? Who is most likely to win each game? Why? Red and Green are equally likely because there is the same amount for each. Green is more likely because there is a bigger amount for green than red. red is more likely because there is a bigger amount for red than green.

9 What is probability? Probability is a measure of how likely it is that an event will happen. A probability is indicated by a number between 0 and 1. Some events are certain to happen, while others are impossible. In most cases, the probability of an event happening is somewhere between certain and impossible.

10 Description Some events are impossible. These events have a probability of 0. Some events are certain. These events have a probability of 1. Some events are classified as equally likely to happen or to not happen. These events have a probability of 1 2. Some events are more likely to happen than not to happen. These events have a probability that is greater than 0.5. These events could be described as likely to occur. Some events are less likely to happen than not to happen. These events have a probability that is less than 0.5. These events could be described as unlikely to occur. Example You have a bag with two green cubes, and you select one at random. Selecting a blue cube is an impossible event. You have a bag with two green cubes, and you select one at random. Selecting a green cube is a certain event. You have a bag with one blue cube and one red cube, and you randomly pick one. Selecting a blue cube is equally likely to happen or not to happen. If you have a bag that contains eight blue cubes and two red cubes, and you select one at random, it is likely that you will get a blue cube. If you have a bag that contains eight blue cubes and two red cubes, and you select one at random, it is unlikely that you will get a red cube.

11 Where does it fall on the scale? Decide where each event would be located on the scale above. Place the letter for each event on the appropriate place on the probability scale. Event: A. You will see a live dinosaur on the way home from school today. 0 B. A solid rock dropped in the water will sink. 1 C. A round disk with one side red and the other side yellow will land yellow side up when flipped..5 D. A spinner with four equal parts numbered 1 4 will land on the 4 on the next spin..25 E. Your full name will be drawn when a full name is selected randomly from a bag containing the full names of all of the students in your class. F. A red cube will be drawn when a cube is selected from a bag that has five blue cubes and five red cubes..5 G. Tomorrow the temperature outside will be 250 degrees. 0 Smaller than.25 but larger than 0

12 Design In your group In your group come up with a scenario that will 1. Have a probability 1 2. Have a probability 0 3. Have a probability.5

13 Decide the scale A shape will be randomly drawn from the box shown below. Decide where each event would be located on the probability scale. Then, place the letter for each event on the appropriate place on the probability scale. Event: A. A circle is drawn. 0, not likely B. A square is drawn. likely C. A star is drawn. Not likely D. A shape that is not a square is drawn. likely

14 What is approximate probability Approximate probability is the likely hood that an event will occur given a random sample of probabilities. We make an educated guess about what will happen given the outcomes of the data provide.

15 Approximate Probability A student brought a very large jar of animal crackers to share with students in class. Rather than count and sort all the different types of crackers, the student randomly chose 20 crackers and found the following counts for the different types of animal crackers. Estimate the probability of selecting a zebra. 3 out of 20 chance Or 3 20 x 100 = 15% chance This is approximate probability because we did not sort all of the animal shapes to calculate the actual probability.

16 Approximate Probability Each of the 20 students in Mr. Anderson's class flipped a coin ten times and recorded how many times it came out heads. How many heads do you think you will see out of ten tosses? Would it surprise you to see 4 heads out of ten tosses? Explain why or why not. Total number of flips : 10 x 20 = 200 Total number of heads: out of 200 flips are heads x 100 = 53.5% chance of getting a head So it would not surprise me to get 4 heads out of 10 tosses because 4 of 10 is 40% and we have a 53.5% chance to get a heads according to this data.

17 Exit Ticket Decide the scale for each of the following events. a. A vowel will be picked when a letter is randomly selected from the word lieu. b. A vowel will be picked when a letter is randomly selected from the word math. c. A blue cube will be drawn from a bag containing only five blue and five black cubes. d. A red cube will be drawn from a bag of 100 red cubes. e. A red cube will be drawn from a bag of 10 red and 90 blue cubes.