Homework answers / question archive / Question 1: Specific Motors of Detroit has developed a new Automobile known as the M car
Question 1:
Specific Motors of Detroit has developed a new Automobile known as the M car. 24 M cars and 28 J cars (from Japan) were road tested to compare milespergallon (mpg) performance. Sample 1(MCars) Sample 2 (J Cars)
Sample 1(MCars) 
Sample 2 (J Cars) 
n1 = 24 
n2= 28 
X1 = 29.8 
X2 = 27.3 
S1 = 2.56 S2 = 1.81
Calculate a 90% confidence interval for the difference between mpg performance of the 2 car models.
A.) The manager claims that there is no difference in the mpg performance of M and J cars.
B.) Write out the null and alternative hypothesis to test the manager’s claim.
C.) Calculate the test statistic.
D.) Calculate the pvalue.
E.) At a 5% level of significance do you accept or reject Ho.
Question 2:
Twenty undergraduate students are discussing the number of hours they need to study statistics for the final exam. They have three different plans. The entries in the table for the different plans are:
Plan 1 
Plan 2 
Plan 3 
7.5 

4.5 

The resulting ANOVA table is shown below:
Test the hypothesis that the mean of the 3 plans are the same, at 5% level of significance. State the null and alternative hypotheses.
Question 3:
Suppose that Vancouver School Board wants to examine the effect of new curriculum on three different discitis: Vancouver, Richmond and Delta. It collects a sample of students’ marks in the National Beard Exam of three different schools from each district.
Using the hypothetical data provided below, test whether the mean of students’ marks for each district is the same.
Use α=5%.
Table ANOVA.1
Vancouver district 
Richmond district 
Delta district 
643 
469 
484 
702 
525 
402 
655 
427 
456 
666.67 473.67 447.33
S: 31.18 49.17 41.68
State the null and alternative hypotheses.
Calculate the appropriate test statistic
Obtain the Critical Value
Question 4:
A university administrator wants to investigate if there is any relationship between international student’s IELTS exam score (X) and the number of admitted students at university (Y). A sample of 16 students is randomly selected and the results are summarized in the ANOVA table below:
ANOVA 


df 
SS 
MS 
F 
Regression 
1 
372.707 
372.707 
42.927 
Residual 
15 
130.234 
8.682 

Total 
16 
502.941 



Coefficients 
Standard Error 
t Stat 
Pvalue 
Intercept 
45.623 
3.630 
12.569 
0.000 
Price 
0.107 
0.016 
6.552 
0.000 
What is the estimated regression equation that relates the number of admitted students at university (Y) to the exam score in IELTS (X)?
What is the estimated number of admitted students if a student got a score of 8.0 in IELTS?
Is the regression relationship significant? Use the pvalue approach and 2% level of significance
Compute the coefficient of determination between the exam score in accounting and the exam score in mathematics. Interpret the result in the context of the problem.
Question 6:
Obtain regression equation of Y on X and estimate Y when X=60 from the following:
55 
43 
45 
65 
43 
60 
65 
75 
70 
65 
55 
53 
40 
35 