Populations and Samples 1-1 Populations and Samples Warm Up Problem of the Day Lesson Presentation Course 2

Populations and Samples Course 2 1-1 Populations and Samples Warm Up Simplify. 1. 72  10 2. 26 + 75 720 101 3. 127  34 4. 125  25 93 5 5. 1,234 + 843 6. 851  653 2,077 198 7. 43  12 8. 657  3 516 219

Populations and Samples Course 2 1-1 Populations and Samples Problem of the Day Why are both products the same? 26  51 = 1,326 39  34 = 1,326 26  51 = (2  13)  (3  17); 39  34 = (3  13)  (2  17); the factors are 2, 3, 13, and 17

Populations and Samples Course 2 1-1 Populations and Samples Learn to identify populations and random samples.

Populations and Samples Course 2 1-1 Populations and Samples Vocabulary population sample random sample

Populations and Samples Course 2 1-1 Populations and Samples A population is the whole or entire group. A sample is a smaller group of people or objects chosen for study from a larger group or population.

Populations and Samples Course 2 1-1 Populations and Samples When scientists track migratory animals, they cannot track each animal. Instead, they tag a sample of the population and track the sample. They use the sample to gather statistical data about the population.

Populations and Samples Course 2 1-1 Populations and Samples Additional Example 1A: Identifying Populations and Samples Identify the population and sample in the situation. A. The mayor surveys 1,000 voters to see if they approve of the job she is doing. Population Sample All registered voters 1,000 voters who are surveyed

Populations and Samples Course 2 1-1 Populations and Samples Additional Example 1B: Identifying Populations and Samples Identify the population and sample in the situation. B. The coach wants to know which uniform the basketball team wants to wear, but he only asks the starting five. Population Sample The basketball team The starting five

Populations and Samples Course 2 1-1 Populations and Samples Additional Example 1C: Identifying Populations and Samples Identify the population and sample in the situation. C. The local movie theater surveys customers to find out which brand of popcorn customers prefer. Population Sample All customers Customers who respond to survey

Populations and Samples Course 2 1-1 Populations and Samples Try This: Example 1A Identify the population and sample in the situation. A. A teacher surveys 50 students in the seventh grade to find out the types of movies seventh graders like. Population Sample All seventh graders 50 students who are surveyed

Populations and Samples Course 2 1-1 Populations and Samples Try This: Example 1B Identify the population and sample in the situation. B. A scientist studying corn production measures the amount of corn produced by one acre of corn plants. Population Sample All corn plants one acre corn

Populations and Samples Course 2 1-1 Populations and Samples Try This: Example 1C Identify the population and sample in the situation. C. A magazine surveys its subscribers to ask what articles they liked in the latest issue. Population Sample All subscribers The subscribers who answer the survey

Populations and Samples Course 2 1-1 Populations and Samples For a sample to be useful, it must be representative of the population. If it is not, then the information gathered from the sample will be inaccurate. One type of representative sample, known as a random sample, gives every member of the population an equal chance of being chosen.

Populations and Samples Course 2 1-1 Populations and Samples Additional Example 2A: Identifying Random Samples A teacher questions students about which day to give a math test. Tell whether each sampling method is random. Explain your answer. A. The teacher asks the first five students who walk into the classroom. This sampling method is not random. All students not in the room at the time have no chance of being chosen.

Populations and Samples Course 2 1-1 Populations and Samples Additional Example 2B: Identifying Random Samples A teacher questions students about which day to give a math test. Tell whether each sampling method is random. Explain your answer. B. The teacher writes the name of each student on a piece of paper and questions the students whose names are drawn. This sampling method is random. Each student has an equal chance of being chosen.

Populations and Samples Course 2 1-1 Populations and Samples Additional Example 2C: Identifying Random Samples A teacher questions students about which day to give a math test. Tell whether each sampling method is random. Explain your answer. C. The teacher questions the students in the first desk in each row. This sampling method is not random. Students not in the first desk do not have a chance of being chosen.

Populations and Samples Course 2 1-1 Populations and Samples Try This: Example 2A The owner of a chain of record stores is conducting a survey about the kind of music his customers like. Tell whether each sampling method is random. A. The owner of the chain surveys only customers over the age of 18 who shop at his store. This is not random. Customers under the age of 18 do not have a chance of being chosen.

Populations and Samples Course 2 1-1 Populations and Samples Try This: Example 2B The owner of a chain of record stores is conducting a survey about the kind of music his customers like. Tell whether each sampling method is random. B. The owner randomly selects 200 customers from a list of all his customers. This sampling method is random. Each customer has an equal chance of being chosen.

Populations and Samples Course 2 1-1 Populations and Samples Try This: Example 2C The owner of a chain of record stores is conducting a survey about the kind of music his customers like. Tell whether each sampling method is random. C. The owner surveys customers whose last names begin with the letter r. This sampling method is not random. Customers whose last names do not begin with the letter r do not have a chance of being chosen.

Populations and Samples Course 2 1-1 Populations and Samples Lesson Quiz: Part 1 1. A TV ratings service is surveying residents of Orlando who bought TVs in the last month about their favorite TV show. A. Identify the sample. B. Identify the population. people who bought TVs in the last month all residents of Orlando

Populations and Samples Course 2 1-1 Populations and Samples Lesson Quiz: Part 2 2. The school newspaper is conducting a survey on the students’ favorite subjects. Tell whether each sampling method is random. Explain your answers. A. The newspaper surveys senior students in a math class. B. The newspaper surveys every twentieth student entering the school. No; only seniors are being surveyed. No; not every student entering the school has a chance to be chosen.