In: Statistics and Probability
Given here are the data from a dependent variable and two
independent variables. The second independent variable is an
indicator variable with several categories. Hence, this variable is
represented by x2, x3, and
x4. How many categories are there for this
independent
variable? Use a computer to perform a multiple regression analysis
on this data to predict y from the x values.
Discuss the output and pay particular attention to the dummy
variables.
y | x1 | x2 | x3 | x4 |
11 | 1.9 | 1 | 0 | 0 |
3 | 1.6 | 0 | 1 | 0 |
2 | 2.3 | 0 | 1 | 0 |
5 | 2.0 | 0 | 0 | 1 |
9 | 1.8 | 0 | 0 | 0 |
14 | 1.9 | 1 | 0 | 0 |
10 | 2.4 | 1 | 0 | 0 |
8 | 2.6 | 0 | 0 | 0 |
4 | 2.0 | 0 | 1 | 0 |
9 | 1.4 | 0 | 0 | 0 |
11 | 1.7 | 1 | 0 | 0 |
4 | 2.5 | 0 | 0 | 1 |
6 | 1.0 | 1 | 0 | 0 |
10 | 1.4 | 0 | 0 | 0 |
3 | 1.9 | 0 | 1 | 0 |
4 | 2.3 | 0 | 1 | 0 |
9 | 2.2 | 0 | 0 | 0 |
6 | 1.7 | 0 | 0 | 1 |
Appendix A Statistical Tables
Number of categories =
.
The regression equation is: y− =
+
x1 +
x2 -
x3 -
x4 (Round answers to 3 decimals.)
Answer:
Given Data
Using Excel complite this question
Output of Multiple regression is
Here number of category is 4
Suppose those category are A = ( 0 ,0,0)
B = (1,0,0)
C = (0,1,0)
D= (0,0,1)
this are the 4 category .
and least square regression equation is
is the regression equation .
If you want to predict first independent variable X1 = 2.2 and second independent varable catedory B=(1,0,0)
then predict Y value using this
= 7.90286 + 1.458051 (1) - 5.88127 (0) - 4.10836 *(0)
= 7.90286 +1.458051
=9.38337
is the predicted value of Y for category B.