simple linear regression

Question 1

bivariate data

Answer 1

data we get when we work with exactly two quantitative measurements on each individual

Question 2

variables in bivariate data

Answer 2

response (y)—> measures out some
explanatory (x) —> explains changes in y

Question 3

scatterplot characteristics

Answer 3

DONT FUCK SHIT UP
D - direction (positive or linear)
F - form (linear or clearly not linear)
S - strength (weak,moderate,strong)
U (unusual) - outliers

Question 4

correlation

Answer 4

r
quantifies the strength and direction of the linear relationship between variables x&y
always between -1 and 1
not resistant/ strongly affected by outliers

Question 5

regression line

Answer 5

that = bo + b1x

Question 6

residuals

Answer 6

observed response- estimated response
e = y-hat
smaller residuals = line describes the linear relationship in data better

Question 7

least squares regression line

Answer 7

produces the line that fits the data best
- minimizes the sum of the squared residuals

Question 8

R^2 value

Answer 8

coefficient of determination
describes the fraction of variation in the response variable that is explained by the least-squares regression line
ex: r^2 = 0.75
about 75% of the variation in y can be explained by x