Transcript Glencoe Pre
Over Lesson 13–5 How many countries won between 1 and 10 medals? A. 18 C. 12 B. 16 D. 10 How many countries won medals in the 1998 Winter Olympics? A. 32 B. 28 A. C. 24 D. 10 Which country won the B. greatest number of medals? C. A. USA B. China C. Canada D. cannot be determined D. A B C D You have already simplified ratios. (Lesson 6–1) • Find the probability of simple events. • Predict the actions of a larger group. • outcomes Possible result of a probability experiment • simple event One outcome or a collection of outcomes. • probability The ratio of the number of ways a certain event can occur to the total number of possible outcomes • sample space The set of all possible outcomes • random Outcomes occur at random if each outcome is equally likely to occur (it is not fixed or has been manipulated) • theoretical probability What should occur in a probability • experimental probability experiment What actually occurs in a probability experiment Find Probability Suppose a number cube is rolled. What is the probability of rolling a 4 or a 5? There are 2 numbers on the number cube that are a 4 or a 5: 4 and 5. There are 6 possible outcomes: 1, 2, 3, 4, 5, and 6. Answer: Suppose a number cube is rolled. What is the probability of rolling a number that is divisible by 3? A. AnsA B. AnsB C. AnsC D. AnsD A. B. C. D. A B C D Find Probability Suppose that two number cubes are rolled. Find the probability of rolling two identical numbers. Make a table showing the sample space when rolling two number cubes. Find Probability There are 6 outcomes in which the two numbers are identical. Answer: Suppose that two number cubes are rolled. Find the probability of rolling two numbers whose sum is 8. A. B. C. D. A. B. C. D. A B C D Find Experimental Probability A coin was tossed 40 times and heads came up 18 times. Find the experimental probability of getting tails for this experiment. Then compare the experimental probability with the theoretical probability. Find Experimental Probability Answer: So, tossing tails in the experiment occurred more often than expected. BASKETBALL Brian is shooting baskets with a basketball. He makes 13 shots and misses 9 shots. Determine the experimental probability of Brian making a shot. A. B. C. D. A. B. C. D. A B C D Make a Prediction SPORTS Miss Newman surveyed her class to see which sports they preferred watching. 44% preferred football, 28% basketball, 20% soccer, and 8% tennis. Out of 560 students in the entire school, how many would you expect to say they prefer watching basketball? Understand You know that 28% prefer basketball. You need to find how many students out of 560 prefer basketball. Plan Use the percent proportion to find 28% of 560. Make a Prediction Solve part whole The percent is 28% and 560 is the whole. Let a represent the part. percent Make a Prediction Answer: You can expect about 157 students to say they prefer watching basketball. Check Estimate: 28% is about 25%. 25% of 600 is 150. So, 157 is reasonable. COLORS The students in an art class were surveyed about their favorite color. 32% preferred blue, 29% preferred red, 23% preferred yellow, and 16% preferred green. Out of 450 students in the entire school, how many would you expect to say they prefer red? A. about 6 B. 29 C. about 131 D. 144 A. B. C. D. A B C D