week nine

Question 1

what are the two measures of association?

Answer 1

covariance
correlation
(the behaviour of one does not cause a change on the behaviour of another)

Question 2

what is covariance?

Answer 2

positive values represent positive linear relationship. whereas, it is the opposite for negative values, it is denoted as cov(x,y) if the dataset refers to a sample

if the line of best fit is flat, the covariance is zero

Question 3

why can the regression value ‘r’ be misleading?

Answer 3

it implies nothing about the slope

it may miss out some outliers

Question 4

what are the steps to casualty?

Answer 4

theoretical rationale linking purported cause and effect

show that the independent variable took place before the dependency variable

shaw that there is an association with the cause and the outcome

rule out any factors that may be related to the outcome