In: Statistics and Probability
The following regression output was obtained from a study of architectural firms. The dependent variable is the total amount of fees in millions of dollars.
Predictor | Coefficient | SE Coefficient | t | p-value | ||||||||
Constant | 7.617 | 2.998 | 2.541 | 0.010 | ||||||||
x1 | 0.224 | 0.069 | 3.246 | 0.000 | ||||||||
x2 | ? | 1.144 | 0.559 | ? | 2.047 | 0.028 | ||||||
x3 | ? | 0.071 | 0.120 | ? | 0.592 | 0.114 | ||||||
x4 | 0.675 | 0.354 | 1.907 | 0.001 | ||||||||
x5 | ? | 0.057 | 0.025 | ? | 2.280 | 0.112 | ||||||
Analysis of Variance | ||||||||||
Source | DF | SS | MS | F | p-value | |||||
Regression | 5 | 2,113.40 | 422.7 | 7.37 | 0.000 | |||||
Residual Error | 48 | 2,751.10 | 57.31 | |||||||
Total | 53 | 4,864.50 | ||||||||
x1 is the number of architects employed by the company.
x2 is the number of engineers employed by the company.
x3 is the number of years involved with health care projects.
x4 is the number of states in which the firm operates.
x5 is the percent of the firm’s work that is health care?related.
Write out the regression equation. (Negative answers should be indicated by a minus sign. Round your answers to 3 decimal places.)
How large is the sample? How many independent variables are there?
c-1. At the 0.05 significance level, state the decision rule to test: H0: ?1 = ?2 = ?3 =?4 = ?5 = 0; H1: At least one ? is 0. (Round your answer to 2 decimal places.)
c-2. Compute the value of the F statistic. (Round your answer to 2 decimal places.)
c-3. What is the decision regarding H0: ?1 = ?2 = ?3 = ?4 = ?5 = 0?
d-1. State the decision rule for each independent variable. Use the 0.05 significance level. (Round your answers to 3 decimal places.)
For x1 | For x2 | For x3 | For x4 | For x5 | ||||
H0: ?1 = 0 | H0: ?2 = 0 | H0: ?3 = 0 | H0: ?4 = 0 | H0: ?5 = 0 | ||||
H1: ?1 ? 0 | H1: ?2 ? 0 | H1: ?3 ? 0 | H1: ?4 ? 0 | H1: ?5 ? 0 | ||||
d-2. Compute the value of the test statistic. (Negative answers should be indicated by a minus sign. Round your answers to 3 decimal places.)
d-3. For each variable, make a decision about the hypothesis that the coefficient is equal to zero.
Write out the regression equation. (Negative answers should be indicated by a minus sign. Round your answers to 3 decimal places.)
y=7.617+0.224x1-1.144x2-0.071x3+0.675x4-0.057x5
How large is the sample? How many independent variables are there?
n=53+1=54
n=54
5 independent variables x1x2,x3,x4,x5
k=5(independent
c-1. At the 0.05 significance level, state the decision rule to test: H0: ?1 = ?2 = ?3 =?4 = ?5 = 0; H1: At least one ? is 0. (Round your answer to 2 decimal places.)
F=7.37
p=0.000
p<0.05
Reject null hypothesis.
Accept alternative Hypothesis.
At least one ? is 0
c-2. Compute the value of the F statistic
F=7.37
c-3. What is the decision regarding H0: ?1 = ?2 = ?3 = ?4 = ?5 = 0
Atleast one ? is 0
d-1. State the decision rule for each independent variable.
For x1 p=0.000,p<0.05
H1: ?1 ? 0
For x2 p=0.028,p<0.05 Reject Ho Accept H1
H1: ?2 ? 0
For x3,p=0.114,p>0.05 Accpet H0.
H0: ?3 = 0
For x4 ,p=0.001,p<0.05 Reject Ho
H1: ?4 ? 0
For x5 ,p=0.112,p>0.05Accept Ho
H0: ?5 = 0
d-2. Compute the value of the test statistic.
for x1 ,t=3.235
for x2 t=-2.047
for x3 t=-0.592
for x4 ,t=1.907
for x5,t=-2.280
Solutiond3:
x1,x2,x4 are significant variables as p<0.05
x3,x5 are non significant variables as p>0.05