8.11c Random Samples

8.11c Random Samples

​EQ- How do we generate random samples?

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​LO- We will learn about random samples and how to generate conclusions from them.

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​CO- I will work on recognizing and generating random sample problems.

​Vocabulary

Survey- method of collecting information.

Population- Group being surveyed/studied. (sometimes very large)

Sample- part of a group being surveyed (usually used to save time and money)

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Draw

Write in which is the population (p) and which is the sample (s).

To get valid results, you must have have an unbiased sample. An unbiased sample is selected to accurately represent the entire population.

In a biased sample, ​one or more parts of the population are favored over others.

Multiple Choice

• Biased

• Unbiased

Open Ended

A real estate agent surveys people about their housing preferences at an open house she is hosting for a luxury condominium. Eighty five percent of the people who responded preferred owning their own home. Is this conclusion valid? Justify your answer.

Using Sampling to Predict

​A valid sampling method uses unbiased samples. If a sampling method is valid, you can make generalizations about the population.

​I do

​A cafeteria wants to offer frozen yogurt. The workers survey 40 random customers about their favorite type of yogurt. The results of the survery are shown in the table. If 200 yogurts are ordered, how many should be chocolate?

​We do

A radio station is deciding which new program to air. It randomly surveys people at a department store. Is the sample method valid? If so, suppose the station surveys 400 more people. How many people willl prefer the sports program?

Draw

About ow many students want a tiger out of the total population?

Poll

Are you ready to practice?

​Practice