Week 9 day 1

Question 1

What is a Pearson’s correlation?

Answer 1

It is a measure of correlation.
It assumes that the relationship is linear.

Question 2

What is the null hypothesis for a correlation?

Answer 2

The null hypothesis for a correlation is that the correlation is 0.

Question 3

What test can you do if your data does not appear to be a linear relationship?

Answer 3

A spearman test, which has a test stat rho.

Question 4

What does Spearman’s test assume?

Answer 4

Spearman’s test, unlike Pearson’s test, does not assume that the data has a linear relationship.
It does, however, assume that the relationship is monotonic. This means that the trend of the data is going up or down.

Question 5

What does monotonic mean?

Answer 5

A relationship that moves in one direction.

Question 6

How does a Spearman’s test work?

Answer 6

It converts data from raw values to ranks and then it does a Pearson correlation.

Question 7

A regression is done between two numeric variables - both predictor and outcome are numberic.

True?

Answer 7

Yes.