Grasple Flashcards
1
Q
What is the value of Pearson’s r when there is no correlation?
A
r=0
2
Q
Why is it common to find that Pearson’s r!=0 even though there is no correlation?
A
Because of sampling variation.
3
Q
What is the right choice of significance test when dealing with Pearson’s r?
A
t-test
4
Q
Give the formula for the t-test for Pearon’s r:
A
t = r* ROOT( (n-2) / (1-r^2))
5
Q
What is the degrees of freedom when dealing with Pearson’s r?
A
n-2
6
Q
What is the formula for the residual error in linear regression?
A
y - y^
with y^= y hat
7
Q
How do you calculate the t-value of the intercept in regression?
A
t = (b0-0) / s.b0
So the estimated value of b0 - the value under the null hypothesis, then divided by the standard deviation of b0.
8
Q
A
