Section 11.8- Samples and Surveys
Essential Question: How can we use samples to find reliable statistical information about a population?
Think about how many TOTAL fish there are in the lake.
YouTube Video Questions
Listen carefully to the videos and complete the following questions.
1. In a random sample, each member of the population is ______to be chosen.
2. The larger the sample size, the more ______it’ll be ______of the population.
3. How is a stratified random sample different than a simple random sample?
4. The English classes in the school represent the possible ______for your sample.
5. What two types of samples do you want to avoid because they are NOT RANDOM?
Bias- when part of a population is ______or ______
Break Down of Polling Sizes
Largest / Intermediate / SmallestGoal: Use ______polling size to generate conclusion about the ______group.
Example 1: Analyzing Sampling Methods
A poll of ______in the population is called a ______. When does the government use this type of polling?
Study Methods
- Observational study
- ______or observe members of a study in a way that does NOT affect the study
- Controlled experiment
- Divide sample into ______groups
- Impose a treatment on one group, but not on the other
- Similar to ______experiments
- Survey
- Ask ______member of a sample a set of questions
NOTE: A poorly designed study can result in unreliable statistics. You should always ANALYZE a study’s methods before making general conclusions about the population.
Example 2: Analyzing Study Methods
a. Which type of study method is described in each situation?
b. Should the sample statistics be used to make a general conclusion about the population?
D. A pharmaceutical company asks for volunteers to test a new drug to treat high blood pressure. Half of the volunteers will be given the drug, and half will be given a placebo.
Wrap-Up Activity
Answer Yes or No for each question in Survey A.
Answer Yes or No for Survey B.
Were your answers different to the questions? If so, why?
Group Work:
Complete #1, 2, 4, 5.
HW: p. 728-730 #6-11, 17-19, 21-23, 25