In: Statistics and Probability
The annual sales of American made vehicles (in 1000 vehicles) to foreign countries has been estimated as follow:
E(Yi)=200.5 - 4.5X1 + 1.8X2i - 3.76X3 R2=0.73
(1.081)* (-2.73)* (3.932)* (-5.03)* n=44, F=18.56
Where E(Yi)= annual average number of vehicles sold to foreign countries (in 1000 vehicles), X1=the annual average price of all vehicles sold to foreign countries (in $100), X2= average foreign per capita income (in $1000), and X3 is a binary variable that assumes a value of 0 when there is no major political turmoil in foreign countries in a year, and a value of 1 when there is a major turmoil in foreign countries in a year.
*Numbers inside parentheses are t-statistics.
a. Explain the meaning of each estimated coefficient (except the intercept) in the context of this problem and plain English.
b. Use alpha of 0.05 to determine which estimated coefficients are significant (different from zero) including the intercept. Make sure all null hypotheses and alternative hypotheses are explained in the context of this model and plain English. Also, find the approximate P-values. What are your conclusions?
c. Check the overall significance (or validity) of the entire model using alpha=0.05. Make sure Ho,Ha, and your conclusion are explained in plain English. What is the approximate p-value?
d. Explain the meaning of multiple coefficient of determination in the context of this model.
Please show work
E(Yi)=200.5 - 4.5X1 + 1.8X2i - 3.76X3
where
E(Yi)= annual average number of vehicles sold to foreign countries (in 1000 vehicles)
X1=the annual average price of all vehicles sold to foreign countries (in $100),
X2= average foreign per capita income (in $1000), and
X3 is a binary variable that assumes a value of 0 when there is no major political turmoil in foreign countries in a year, and a value of 1 when there is a major turmoil in oreign countries in a year.
a)
interpritation
if the value of X1=the annual average price of all vehicles sold to foreign countries (in $100), i incresed by 1 then value of annual average number of vehicles sold to foreign countries (in 1000 vehicles) is decreased by 4.5
if the value of X2= average foreign per capita income (in $1000) is ncresed by 1 then value of annual average number of vehicles sold to foreign countries (in 1000 vehicles) is increased by 1.8
if the value of X3 is a binary variable that assumes a value of 0 when there is no major political turmoil in foreign countries in a year, and a value of 1 when there is a major turmoil in oreign countries in a year. is ncresed by 1 then value of annual average number of vehicles sold to foreign countries (in 1000 vehicles) is decreased by 3.76
b. Use alpha of 0.05 to determine which estimated coefficients are significant (different from zero) including the intercept. Make sure all null hypotheses and alternative hypotheses are explained in the context of this model and plain English. Also, find the approximate P-values. What are your conclusions
first intercept is denoted as bo
the hypothsis
H0:b0=0 vs H1:b0≠0
test statisric value is t=1.081
the p value is 0.2862
the p value is grater than 0.05
so we accept H0 b0=0
i.e the intercept is insinificant for the model
first slpoe t is denoted as b1
the hypothsis
H0:b1=0 vs H1:b1≠0
test statisric value is t=-2.73
the p value is 0.0094
the p value is less than 0.05
so we reject H0 i.e b1≠0
i.e the x1 is sinificant for the model
nnual average price of all vehicles sold to foreign countries (in $100), is sinificant for the model
second slpoe is denoted as b2
the hypothsis
H0:b2=0 vs H1:b2≠0
test statisric value is t=-3.932
the p value is 0.0003
the p value is less than 0.05
so we reject H0 i.e b2≠0
i.e the x2 is sinificant for the model
average foreign per capita income (in $1000), is sinificant for the model
Third slpoe is denoted as b3
the hypothsis
H0:b3 =0 vs H1:b3≠0
test statisric value is t=--5.03
the p value is 0.0001
the p value is less than 0.05
so we reject H0 i.e b3≠0
i.e the x3 is sinificant for the model
is a binary variable that assumes a value of 0 when there is no major political turmoil in foreign countries in a year, and a value of 1 when there is a major turmoil in oreign countries in a year. is sinificant for the model
c. Check the overall significance (or validity) of the entire model using alpha=0.05. Make sure Ho,Ha, and your conclusion are explained in plain English. What is the approximate p-value?
the hpothesis is
H0:b1=b2=b3=0
H1: at least one bi is different from zero i=1,2,3
Test statistic value is
F=18.56
the p value is 0.0001
the p value is less than 0.05
so we reject H0
at lest one bi is different
the all independent variable is significant for thr model;
d)
Explain the meaning of multiple coefficient of determination
coefficient of determination=R2=0.73
the 73% variation in y is explained by the independent variables