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Warm Up Sept 16 Solve 3 – x = - 4 3x – 7 = 5 3(x + 7) = -10 3(h – 2) + 15 = 18. Lesson 4.1: Organizing and Displaying Data. (Introduction to Data Analysis)
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Warm Up Sept 16 • Solve • 3 – x = - 4 • 3x – 7 = 5 • 3(x + 7) = -10 • 3(h – 2) + 15 = 18
Lesson 4.1: Organizing and Displaying Data (Introduction to Data Analysis) When we analyze data, we can see how individual pieces of information can contribute to a larger meaning. Just like in Robert Silvers photo collage below.
By the end of this chapter you will be able to: • Collect statistical data and organize it • Make sense of your data via different types of graphs and measures of center • Analyze the strengths and weaknesses of each kind of graph and measure of center to determine which one provides the best representation of data based on the situation • State a conclusion about your data based on your organization and analyzing of data
Collecting Data: There are 2 types of data collection. Census – surveys the entire population. Sample – surveys a small portion or subset of the population Examples: • Census • 1. Asking all the 9th graders at PHS what their favorite subject in school is. • Sample • 2. Asking 10 students in Mr. Castillo’s 6th hour math class what their favorite subject is.
You try these: • 1. The cafeteria asked 50 students what should be served for lunch. • Sample • 2. All the residents of San Tan Ranch neighborhood were surveyed to determine their opinions about a new road planned to run thru their park. • Census
Why we use sampling vs. census. • Usually impossible to get data from an entire population. • Cheaper • Takes less time.
Random vs. Bias • Random Sample– every person in population has an equal chance of being selected. • Bias – is not random and it favors certain outcomes Examples: • 1. You want to find out the favorite sport of high school students. You ask only the girls volleyball team. • Biased • 2. You ask those coming out of Fry’s what their favorite grocery store is. • Biased
3. A survey asks a random group of high school students what their favorite music is. • Random • 4. Every 10th student is selected and asked what could improve school lunch. • Random
Use the data table to organize results: List the states from greatest to least for money spent on Emergency: List the damage category in order by total from least to greatest:
Answers: Missouri, Iowa, Illinois, Minnesota, Kansas, South Dakota, North Dakota, Wisconsin, Nebraska Agricultural, Other, Emergency, Utilities Are these measures a sample or a census?
Summary Why are these biased? • 1. Police officer in a uniform asks people how many times they have used drugs. • 2. Asking math teachers about their attitude towards standardized math tests.
Thinking about our data: • What could you conclude from our data? • Is the table above a census or a sample? • Is it biased or random (unbiased)? • How could we bias our data, if we wanted to say that the heart rates of students at Perry are higher than students at other high schools?