Ch. 10 simple linear regression Flashcards
1
Q
What is y-hat? What does the hat mean in a linear regression?
A
Y_i-hat = B_o-hat + B_i-hat * X_i
The hat is expected value of that data point - where that x-value is on a least-squares line
2
Q
How do you find the sum of squares of errors?
A
Q = sum of all e_i^2
where e_i is the difference between y_i and y_i-hat
3
Q
How do you get the point where Q (e.g. sum of least-squares) is smallest?
A
Differentiate with respect to B_o and B_1, equal them to 0.
