Week 6 ADDENDUM – Homework/Quiz Review
These are some additional notes that might help with the homework and quiz.
1. You can skip #16 in the homework and #9 and #10 in the quiz. Everyone will be given credit.
The problems look something like this:
In the regression equa
ti
on, ŷ = 5.23 + 2.74x, and n = 24, the mean of x is 12.56, SS
xx
=
55.87 and S
e
= 10.71. A 90% predic
ti
on interval for y when x = 11 is .
2. Review definitions and concepts in the notes.
3. We are developing a regression model to predict weight as function of height.
a. What is the explanatory variable (independent variable)? Answer: height
b. What is the response variable (dependent variable)? Answer: weight
4. In the following regression: ŷ = 27.7 + 3.25x
a. What is the slope? Answer: 3.25
b. What is the y-intercept? Answer: 27.7
5. Use the following data to construct a regression model:
X 27 34 23 17 18
Y 5 14 8 2 5
Answer: ŷ = -6.61 + 0.56x
Independent (x) Dependen t
(y)
Slope (β1) y-Intercept (β0)
Correlation Coefficient (r)
Coefficient of Determination (r2)
Standard Error
27 5
34 14
23 8
17 2
18 5
0.563655
-6.614990
0.864555
0.747456
2.640119
