Soal UTS Business Statistics - 2011
Tipe ujian
: Open Memory Sheet + Tabel Distribusi
Lama ujian : 120Menit (2 jam)
1. B. a two sample test of means.
2. C.
3. A. Scatter diagram
4. D. All of these
5. C. Coefficient of determination is 0.49
6. C. 94% of total variation of one variable is explained by variation in the other
variable.
7. D. 0% to 100% inclusive
8. B. = a + bX
9. D. All of these.
10. B. for each unit increase in X, Y increases by 20.
11. A. Y intercept
12. C. the independent variables and the dependent variable have a linear relationship
13. C. Coefficient of multiple determination
14. A. 19%
15. C. a F statistic
16. B. Multicollinearity
17. B. The "error" or variability in predicting Y
18. B. No relationship exists between the dependent variable and any of the independent
variables
19. A. t-statistic
20. A.
21. C.
22. D. All of them
23. D. All of these
24. C. 0
25. C. 3 and 36
26. A. t-statistic
27. B. +6.3
28. C.
29. A. explained variation relative to total variation.
30. C. The independent variables are highly correlated
II. Simple Calculation (5x2point= 10point):
1. Two samples, one of size 14 and the second of size 13, are selected to test the
difference between two population means. How many degrees of freedom are used to
find the critical value? Assume the population standard deviations are equal. (C. 25)
2. A hypothesis test is conducted at the .05 level of significance to test whether or not
the population correlation is zero. If the sample consists of 25 observations and the
correlation coefficient is 0.60, what is the computed value of the test statistic?
D. 3.60
3. Given the least squares regression equation,
does
equal? C. 4601
4. If the regression equation is
B. 3.2
= 1202 + 1,133X, when X = 3, what
= 2 - 0.4X, what is the value of
5. Given a multiple linear regression equation
when X = - 3?
= 5.1 + 2.2X1 - 3.5X2, what will a unit
increase in the independent variable, X2, mean in the change of
things are held constant? ________ -3.5
assuming other
III. Essay: (3x20point)
1. A sales manager for an advertising agency believes there is a relationship between the
number of contacts and the amount of the sales. To verify this belief, the following
data was collected:
a. What is the dependent variable? C. Amount of sales , What is the independent
variable? B. Number of contacts
b. What is the regression equation? B. = -12.201 + 2.1946X
c. What is the value of the standard error of estimate? A. 9.3104
d. What is the value of the coefficient of correlation? B. 0.9754
e. What is the value of the coefficient of determination? D. 0.9513
f. The 95% confidence interval for 30 calls is C. 46.7, 60.6
2. Calculate & answer the question from Regression result below:
a. What is the standard error of the estimate? C. 11.6985
b. What is the correlation coefficient and coefficient of determination? A. 91.8%
B. 0.958
c. The regression equation is? B. = -12.80894 + 2.179463
d. If testing the hypothesis: H0:
= 0, the computed t – statistic! A. 9.45
e. Estimate the value of
when X = 4. C. 8.20
3. The research is trying to find the best wage of the housemaid per month with
independent variable total room, total floor and washing clothes facility. Based on
summary output below, answer the question.
SUMMARY OUTPUT
Regression Statistics
R
R Square
Adjusted R Square
Standard Error
Observations
0.964920346
0.931071274
0.921671903
51705.84701
26
ANOVA
Regression
Residual
Total
Intercept
TOTAL ROOM(S)
TOTAL FLOOR(S)
WASHING CLOTHES FACILITY
df
3
22
25
SS
7.94483E+11
58816881532
8.533E+11
Coefficients Standard Error
397886.7574
46357.87863
42755.08801
5622.920553
27212.94004
35940.38298
59493.94939
20863.56758
MS
2.64828E+11
2673494615
F
?
t Stat
8.582937122
?
?
?
P-value
1.8E-08
1.36E-07
0.456982
0.009279
a. What is the computed value of “ F ” ? 99.05676
b. What is the computed value of “ t ” statistic for total room, total floor and
washing clothes facility ? total room = 7.603715472 , total floor = 0.757168894 and
washing clothes facility = 2.851571246.
c. Explain the F test and t test, is it reject or accept H0 and the conclusion?
d. Made one of the best regression equation that possible.
e. Compute & analyze the VIF for all independent variabel.
SUMMARY OUTPUT
Regression Statistics
Multiple R
0.964920346
R Square
0.931071274
Adjusted R Square
0.921671903
Standard Error
51705.84701
Observations
26
ANOVA
df
Regression
Residual
Total
Significance
SS
MS
F
F
3 7.94483E+11 2.64828E+11 99.05676 6.24815E-13
22 58816881532 2673494615
25
8.533E+11
Coefficients
Intercept
TOTAL ROOM(S)
Standard
Error
t Stat
P-value
Lower 95%
397886.7574 46357.87863 8.582937122 1.8E-08 301746.4014
42755.08801 5622.920553 7.603715472 1.36E-07 31093.86451
TOTAL FLOOR(S)
27212.94004 35940.38298 0.757168894 0.456982 47322.85228
WASHING CLOTHES FACILITY 59493.94939 20863.56758 2.851571246 0.009279 16225.55849