Introduction to Probability 12-1 Introduction to Probability Course 1 Warm Up Problem of the Day Lesson Presentation

Introduction to Probability Course 1 12-1 Introduction to Probability Warm Up Write each fraction as a decimal and as a percent. 1. 2. 3. 4. 3 4 __ 0.75; 75% 1 2 __ 0.50; 50% 0.2; 22.2% __ 2 9 __ 3 8 __ 0.375; 37.5%

Introduction to Probability Course 1 12-1 Introduction to Probability Problem of the Day What fraction of the numbers from 0 to 99 are divisible by 3? or 34 100 ___ 17 50 __

Introduction to Probability Course 1 12-1 Introduction to Probability Learn to estimate the likelihood of an event and to write and compare probabilities.

Insert Lesson Title Here Course 1 12-1 Introduction to Probability Insert Lesson Title Here Vocabulary probability

Introduction to Probability Course 1 12-1 Introduction to Probability Probability is the measure of how likely an event is to occur.

Introduction to Probability Course 1 12-1 Introduction to Probability Probabilities are written as fractions or decimals from 0 to 1 or as percents from 0% to 100%. The higher an event’s probability, the more likely that event is to happen. Events with a probability of 0, or 0%, never happen. Events with a probability of 1, or 100%, always happen. Events with a probability of 0.5, or 50%, have the same chance of happening as of not happening.

Introduction to Probability Course 1 12-1 Introduction to Probability Impossible Unlikely As likely as not Likely Certain 0 0.5 1 2 1 __ 0% 100% 50%

Introduction to Probability Insert Lesson Title Here Course 1 12-1 Introduction to Probability Insert Lesson Title Here Additional Example 1: Estimating the Likelihood of an Event Write impossible, unlikely, as likely as not, likely, or certain to describe each event. A. You roll an even number on a standard number cube. B. February has 28 days. as likely as not certain A standard number cube is numbered from 1 to 6. Helpful Hint

Introduction to Probability Insert Lesson Title Here Course 1 12-1 Introduction to Probability Insert Lesson Title Here Additional Example 1: Estimating the Likelihood of an Event Write impossible, unlikely, as likely as not, likely, or certain to describe each event. C. This spinner lands on blue. D. This spinner lands on an odd number. unlikely impossible

Insert Lesson Title Here Course 1 12-1 Introduction to Probability Insert Lesson Title Here Check It Out: Example 1 Write impossible, unlikely, as likely as not, likely, or certain to describe each event. A. You guess a number between 1 and 1,000. B. You will roll an odd number on a standard number cube. unlikely as likely as not A standard number cube is numbered from 1 to 6. Helpful Hint

Insert Lesson Title Here Course 1 12-1 Introduction to Probability Insert Lesson Title Here Check It Out: Example 1 Write impossible, unlikely, as likely as not, likely, or certain to describe each event. C. This spinner lands on green. D. This spinner lands on an even number. unlikely certain

Introduction to Probability Insert Lesson Title Here Course 1 12-1 Introduction to Probability Insert Lesson Title Here Additional Example 2: Writing Probabilities A. The weather report gives a 75% chance of snow. Write this probability as a decimal and as a fraction. Write as a decimal. 75% = 0.75 Write as a fraction in simplest form. 75% = = 75 100 ___ 3 4 __ B. The chance of being chosen is 0.8. Write this probability as a fraction and as a percent. Write as a fraction in simplest form. 0.8 = = 8 10 __ 4 5 Write as a percent. 0.8 = 80%

Introduction to Probability Insert Lesson Title Here Course 1 12-1 Introduction to Probability Insert Lesson Title Here Additional Example 2: Writing Probabilities C. There is a chance of getting a ring. Write this probability as a decimal and as a percent. 7 50 __ = 7 ÷ 50 = 0.14 7 50 __ Write as a decimal. = = = 14% 7 • 2 50 • 2 _____ 7 50 __ 14 100 ___ Write as a percent. In Example 2C, after you find the decimal form of , you can use it to find the percent. 0.14 = 14%. Helpful Hint 7 50 __

Insert Lesson Title Here Course 1 12-1 Introduction to Probability Insert Lesson Title Here Check It Out: Example 2 A. The weather report gives a 25% chance of snow. Write this probability as a decimal and as a fraction. Write as a decimal. 25% = 0.25 Write as a fraction in simplest form. 25% = = 25 100 ___ 1 4 __ B. The chance of being chosen is 0.6. Write this probability as a fraction and as a percent. Write as a fraction in simplest form. 0.6 = = 6 10 __ 3 5 Write as a percent. 0.6 = 60%

Insert Lesson Title Here Course 1 12-1 Introduction to Probability Insert Lesson Title Here Check It Out: Example 2 C. There is a chance of getting a ring. Write this probability as a decimal and as a percent. 4 25 __ = 4 ÷ 25 = 0.16 4 25 __ Write as a decimal. = = = 16% 4 • 4 25 • 4 _____ 4 25 __ 16 100 ___ Write as a percent.

Introduction to Probability Insert Lesson Title Here Course 1 12-1 Introduction to Probability Insert Lesson Title Here Additional Example 3A: Comparing Probabilities On a standard number cube, there is a 50% chance of rolling a multiple of 2 and a 33 % chance of rolling a multiple of 3. Is it more likely to roll a multiple of 2 or a multiple of 3? 1 3 __ Compare: 33 % < 50% 1 3 __ It is more likely to roll a multiple of 2.

Introduction to Probability Insert Lesson Title Here Course 1 12-1 Introduction to Probability Insert Lesson Title Here Additional Example 3B: Comparing Probabilities When you spin a certain spinner, there is a 15% chance that it will land on yellow, a 15% chance it will land on green, and a 70% chance that it will land on purple. Is it more likely to land on purple or on green? Compare: 70% > 15% It is more likely to land on purple than on green.

Insert Lesson Title Here Course 1 12-1 Introduction to Probability Insert Lesson Title Here Check It Out: Example 3A When you spin a certain spinner, there is a 25% chance that it will land on purple, a 35% chance it will land on green, and a 40% chance that it will land on red. Is it more likely to land on red or on green? Compare: 40% > 35% It is more likely to land on red than on green.

Insert Lesson Title Here Course 1 12-1 Introduction to Probability Insert Lesson Title Here Check It Out: Example 3B When you spin a certain spinner, there is a 9% chance that it will land on yellow, a 35 % chance it will land on brown, and a 55 % chance that it will land on blue. Is it more likely to land on brown or on yellow? 1 3 __ 2 Compare: 9% < 35 % 1 3 __ It is more likely to land on brown than on yellow.

Introduction to Probability Insert Lesson Title Here Course 1 12-1 Introduction to Probability Insert Lesson Title Here Lesson Quiz Write impossible, unlikely, as likely as not, likely, or certain to describe each event. 1. The sun will rise tomorrow. 2. You will roll 13 when rolling two dice. 3. There is a 0.125 chance of picking the winning ticket. Write this probability as a fraction and as a percent. 4. At Hamburger Hut, there is a 20% chance of getting a plastic dinosaur cup and a 35% chance of getting a plastic rabbit cup. It is less likely that you will receive a rabbit cup or dinosaur cup? certain impossible , 12.5% 1 8 __ dinosaur cup