Introduction to Statistics for the Social Sciences SBS200 - Lecture Section 001, Spring 2019 Room 150 Harvill Building 9:00 - 9:50 Mondays, Wednesdays & Fridays. April 12 http://www.youtube.com/watch?v=oSQJP40PcGI

The Green Sheets

Schedule of readings Before our fourth and final exam (April 29th) OpenStax Chapters 1 – 13 (Chapter 12 is emphasized) Plous Chapter 17: Social Influences Chapter 18: Group Judgments and Decisions

Labs continue next week Lab sessions Labs continue next week

Project 4 - Two Correlations - Two Regression Analyses This lab builds on the work we did in our very first lab. But now we are using the correlation for prediction. This is called regression analysis Project 4 - Two Correlations - Two Regression Analyses

We refer to the predicted variable as the dependent variable (Y) and the predictor variable (X) as the independent variable Why are we finding the regression line? How would we use it? Writing Assignment

regression coefficient We refer to the predicted variable as the dependent variable (Y) and the predictor variable (X) as the independent variable Why are we finding the regression line? How would we use it? regression coefficient (slope) correlation coefficient (“r”)

What variable are we predicting? a. Height of Boys in 1990 (cm) b. Age of boys in 1990 c. Both height and age of boys in 1990

Just for fun let’s do the math If a boy is 8-years old how tall would we predict he would be? Complete prediction “by eye” looking at graph? a. 40 cm b. 80 cm c. 120 cm d. 160 cm Just for fun let’s do the math Y’ = 7.1521 (8) + 64.476 = 122

Just for fun let’s do the math If a boy is 2-years old how tall would we predict he would be? Complete prediction “by eye” looking at graph? a. 40 cm b. 80 cm c. 120 cm d. 160 cm Just for fun let’s do the math Y’ = 7.1521 (2) + 64.476 = 78.8

What variable are we predicting? a. Size of state (square miles) b. Number of letters in name of state c. Both size of state and number of letters

Just for fun let’s do the math If a state has 7 letters in the name (like Arizona) how large would we predict the state to be? Complete prediction “by eye” looking at graph? a. 20,000 square miles b. 30,000 square miles c. 40,000 square miles d. 50,000 square miles Just for fun let’s do the math Y’ = -2,561.5 (7) + 67,884 = 49,953

What variable are we predicting? a. Size of TV (inches) b. Sales price of TV ($) c. Both sales price and size of TV

Just for fun let’s do the math If a TV is 55 inches what would we predict cost to? Complete prediction “by eye” looking at graph? a. $1,500 b. $1,725 c. $2,000 d. $2,225 Just for fun let’s do the math Y’ = 55.044 (55) – 762.25 = $2,235

Just for fun let’s do the math If a TV is 40 inches what would we predict cost to? Complete prediction “by eye” looking at graph? a. $1,500 b. $1,725 c. $2,000 d. $2,225 Just for fun let’s do the math Y’ = 55.044 (40) – 762.25 = $1,439

What variable are we predicting? a. Amount of Wine Consumed b. Death Rate in the Country c. Both Amount of Wine Consumed and Death Rate

Just for fun let’s do the math If a country consumes an average of 8 liters (per capita) what would we predict death rate from heart disease be? Complete prediction “by eye” looking at graph? a. 50 b. 75 c. 100 d. 125 Just for fun let’s do the math Y’ = -23.878 (8) + 266.63 = 75.6

Thank you! See you next time!!