regression analysis

Question 1

what is correlation used for

Answer 1

to quantify linear relationship between two numeric variables

Question 2

what are values for correlation

Answer 2

bound between -1 and 1
0 means no linear relationship
the further away from 0 the stronger the linear relationship
can be positive or negative

Question 3

does variable order matter for correlation

Answer 3

no
you can correlate x-y or y-x

Question 4

what is regression

Answer 4

allows one variable to be predicted from the other

can handle multiple predictors

variables don’t have to be numeric

Question 5

does variable order matter for regression

Answer 5

yes
you predict x from y

Question 6

what do y and x represent

Answer 6

the variables we are looking at

Question 7

what do a and b represent

Answer 7

they explain the linear relationship betweeen y and x

Question 8

what is the regression equation

Answer 8

y = a + bx

Question 9

what is y

Answer 9

the variable being predicted
the “response “ or “outcome” or “dependent” variable ( its value depends on x)

Question 10

what is a

Answer 10

the intercept of the regression line
also known as the constant
this is the point at which the line cross the y axis when x=0

Question 11

what is b

Answer 11

the regression coefficient
the slope ( gradient ) of the regression line
the ledger the value the steeper the slope
the sign indicates the direction of effect
it is the change in y associated with a unit change in x

Question 12

what is x

Answer 12

the “predictor” or “ explanatory” or “independent “ variable

it is the variable we are using to predict y