Warm Up: What is Statistics?

Intro: What is Stats? Statistics: Data: The science (and art) of learning from data. Data: Numbers with a contextual meaning. We use data and Statistics to draw conclusions about a population based on sample information. Data/Statistics Population Inference/Conclusions Sample

Important Terms Population – the group we wish to study Sample – a portion or small group from the population Census – data on everyone in a population Anecdote – limited information about a population, often misleading

4 Themes of Stats Part I: Exploratory Data Analysis The tools and strategies for organizing, displaying, describing, and analyzing data. Part II: Producing Data Designing surveys, experiments, and observational studies that will yield the data necessary to answer a question of interest. Part III: Probability The study of chance behavior. How likely are certain outcomes? Part IV: Inference Draw conclusions about the population based on samples. Test claims and compute estimates.

Traditional Math vs. Stats Focused on calculation/process Usually one correct answer Statistics: Focused on understanding what the answer means A lot of reading and writing

Probability Activity You will do this with a partner from your table. Your partner is sitting next to you. Flip a Hershey’s kiss 40 times. Record each time the kiss lands with the “point up” vs. “not point up.” Calculate the proportion of “point up” landings after these flips: 1, 2, 3, 4, 5, 10, 15, 20, 25, 30, 35, 40 Plot your data on the board.

Chapter 1 - Important Terms Individuals – Objects described by a set of data. Could be people, animals, computer chips, etc. Variable – Characteristics of an individual Categorical variable – places individual into one of several groups Quantitative variable – numerical value describing an individual

Example A sample of cars was taken from those parked in the student parking lot. The following characteristics were recorded for each car: Model, mileage on odometer, color, length of wheelbase, age, and gender of the owner What are the individuals in this data set? b) Which variables are categorical and which are quantitative?

Example A Gallup Poll in 2016 asked 1015 adults the following question: “What do you think is the best long-term investment?” The table below lists the proportion of adults that chose each category. Bonds 0.07 Real Estate 0.35 Gold 0.17 Savings 0.15 Other 0.04 Stocks & Mutual Funds 0.22 1) Use the data to make a bar graph, arranged from largest to smallest percentage. 2) Could you make a pie chart with this data? Why or why not?