MAT 150 Exam 5 Questions and Answers
Question 1
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A random sample of 40
... [Show More] companies with assets over $10 million was surveyed and asked to indicate their industry and annual computer technology expense. The ANOVA comparing the average computer technology expense among three industries rejected the null hypothesis. The Mean Square Error (MSE) was 195. The following table summarized the results:
Education Tax Services Food Services
Number Sampled 10 14 16
Mean Expense (1,000,000s) 2 15.5 20
Based on the comparison between the mean annual computer technology expense for companies in the tax service and food service industries, the 95% confidence interval shows an interval of
-5.85 to 14.85 for the difference. This result indicates that . Select one:
a. There is no significant difference between the two industry technology expenses
b. The interval contains a difference of 20.7
c. Companies in the food service industry spend significantly more than companies in the tax service industry
d. Companies in the food service industry spend significantly less than companies in the tax service industry
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The correct answer is: There is no significant difference between the two industry technology expenses
Question 2
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In ANOVA, the null hypothesis is:
Select one:
a. H0:σ21=σ22=σ23
b. H0:σ21≠σ22≠σ23
c. H0:μ1=μ2=μ3
d. H0:μ1≠μ2≠μ3
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The correct answer is: H0:μ1=μ2=μ3
Question 3
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Given the following ANOVA table for three treatments each with six observations:
Source Sum of Squares df Mean Square
Treatment 1116
Error 1068
Total 2184
What is the computed value of F?
Select one:
a. 7.48
b. 7.84
c. 8.84
d. 8.48
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The correct answer is: 7.84
Question 4
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Which statement is correct about the F distribution? Select one:
a. Cannot be negative
b. Cannot be positive
c. Is the same as the t distribution
d. Is the same as the z distribution
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The correct answer is: Cannot be negative
Question 5
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The annual dividend rates for a random sample of 16 companies in three different industries, utilities, banking, and insurance were recorded. The ANOVA comparing the mean annual dividend rate among three industries rejected the null hypothesis that the dividend rates were equal. The Mean Square Error (MSE) was 3.36. The following table summarized the results:
Utilities Banking Insurance
Number Sampled 5 5 6
Mean Annual Dividend Rate 11.62 15.4 17.4
Based on the comparison between the mean annual dividend rate for companies in the utilities and insurance industries, .
Select one:
a. A confidence interval shows that the mean annual dividend rates are not significantly different
b. The ANOVA results show that the mean annual dividend rates are significantly different
c. A confidence interval shows that the mean annual dividend rates are significantly different
d. The ANOVA results show that the mean annual dividend rates are not significantly different
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The correct answer is: A confidence interval shows that the mean annual dividend rates are significantly different
Question 6
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An electronics company wants to compare the quality of their cell phones to the cell phones from three competitors. They sample 10 phones from each company and count the number of defects for each phone. If ANOVA was used to compare the average number of defects, then the treatments would be defined as:
Select one:
a. The number of cell phones sampled.
b. The average number of defects.
c. The total number of phones.
d. The four companies.
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The correct answer is: The four companies.
Question 7
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When the null hypothesis for an ANOVA analysis comparing four treatment means is rejected,
Select one:
a. Two comparisons of treatment means can be made
b. Four comparisons of treatment means can be made
c. Six comparisons of treatment means can be made
d. Eight comparisons of treatment means can be made
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The correct answer is: Six comparisons of treatment means can be made
Question 8
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Two accounting professors decided to compare the variance of their grading procedures. To accomplish this, they each graded the same 10 exams, with the following results:
Mean Grade Standard Deviation
Professor 1 79.3 22.4
Professor 2 82.1 12.0
At the 5% level of significance, what is the decision regarding the null hypothesis? Select one:
a. Reject the null hypothesis and conclude the variances are different.
b. Fail to reject the null hypothesis and conclude no significant difference in the variances.
c. Reject the null hypothesis and conclude the variances are the same.
d. Fail to reject the null hypothesis and conclude the variances are the same.
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The correct answer is: Reject the null hypothesis and conclude the variances are different.
Question 9
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From each of the two normally distributed populations, independent random samples were selected. n1 =25 from population 1 and n2 = 11 from population 2. The below table gives the means and variances for the two samples:
Sample Size Mean Variance
Sample 1 25 35.4 8.15
Sample 2 11 30.2 3.47
To test (H0:σ21=σ22
versus H1:σ21≠σ22)
What is the degree of freedom for the numerator of F ratio?
Select one:
a. 10
b. 23
c. 34
d. 24
e. 35
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The correct answer is: 24
Question 10
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Two accounting professors decided to compare the variance of their grading procedures. To accomplish this, they each graded the same 10 exams, with the following results:
Mean Grade Standard Deviation
Professor 1 79.3 22.4
Professor 2 82.1 12.0
What is the critical value of F at the 0.05 level of significance? Select one:
a. 5.85
b. 5.35
c. 3.18
d. 4.03
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The correct answer is: 3.18
Question 11
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Independent random samples were selected from each of two normally distributed populations, n1 =25 from population 1 and n2 = 11 from population 2. The below table gives the means and variances for the two samples:
Sample Size Mean Variance
Sample 1 25 35.4 8.15
Sample 2 11 30.2 3.47
To test H0:σ21=σ22
versus H1:σ21≠σ22
What is the degree of freedom for the numerator of F ratio?
Select one:
a. 10
b. 9
c. 34
d. 24
e. 35
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The correct answer is: 10
Question 12
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From each of the two normally distributed populations, independent random samples were selected. n1 =25 from population 1 and n2 = 11 from population 2. The below table gives the means and variances for the two samples:
Sample Size Mean Variance
Sample 1 25 35.4 8.15
Sample 2 11 30.2 3.47
To test H0:σ21=σ22
versus H1:σ21≠σ22
. Find F critical value at 0.10 level of significance.
Select one:
a. 2.73
b. 2.17
c. 1.88
d. 2.25
e. 3.35
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The correct answer is: 2.73
Question 13
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Two accounting professors decided to compare the variance of their grading procedures. To accomplish this, they each graded the same 10 exams, with the following results:
Mean Grade Standard Deviation
Professor 1 79.3 22.4
Professor 2 82.1 12.0
What are the degrees of freedom for the denominator of the F ratio? Select one:
a. 20
b. 18
c. 10
d. 9
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The correct answer is: 9
Question 14
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What is the general form of the regression equation? Select one:
a. Ŷ = ab
b. Ŷ = a+(bX)
c. Ŷ = (a+b)X
d. Ŷ = abX
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The correct answer is: Ŷ = a+(bX)
Question 15
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If r = 0.65, what does the coefficient of determination equal? Select one:
a. 0.1945
b. 0.4225
c. 0.5778
d. 0.8061
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The correct answer is: 0.4225
Question 16
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A sales manager for an advertising agency believes that there is a relationship between the number of contacts that a salesperson makes and the amount of sales dollars earned.
What is the independent variable?
Select one:
a. Salesperson
b. Number of contacts
c. Amount of sales
d. Sales manager
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The correct answer is: Number of contacts
Question 17
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In the regression equation, what does the letter "X" represent? Select one:
a. The Y-intercept
b. The slope of the line
c. The independent variable
d. The dependent variable
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The correct answer is: The independent variable
Question 18
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Using the following information:
Intercept Coefficients
-12.8094
Independent Variable 2.1794
ANOVA
df
SS
MS
F
Regression 1 12323.56 12323.56 90.0481
Residual 8 1094.842 136.8552
Total 9 13418.4
What is the coefficient of determination? Round the percentage to one decimal point. Select one:
a. 91.8%
b. 8.2%
c. 90.0%
d. 136.9%
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The correct answer is: 91.8%
Question 19
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A sales manager for an advertising agency believes there is a relationship between the number of contacts that a salesperson makes and the amount of sales dollars earned.
A regression analysis shows the following results:
Coefficients Standard
Error
t-Stat p-value
Intercept -12.201 6.560 -1.860 0.100
Number of Contacts 2.195 0.176 12.505 0.000
ANOVA
df SS MS F Significance F
Regression 1.00 13555.42 13555.42 156.38 0.00
Residual 8.00 693.48 86.68
Total 9.00 14248.90
X¯
= 33.4. ∑(X−X¯)2
= 2814.4. Rounding to one decimal place, the 95% confidence interval for 30 calls is
. Select one:
a. 55.8, 51.5
b. 51.4, 55.9
c. 46.7, 60.6
d. 31.1, 76.2
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The correct answer is: 46.7, 60.6
Question 20
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If the correlation coefficient between two variables, X and Y, equals zero, what can be said of the variables X and Y?
Select one:
a. The variables are not related.
b. The variables are dependent on each other.
c. The variables are highly related.
d. X causes Y.
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The correct answer is: The variables are not related.
Question 21
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Using the following information:
Coefficients
Intercept -12.8094
Independent Variable 2.1794
ANOVA
df SS MS F
Regression 1 12323.56 12323.56 90.0481
Residual 8 1094.842 136.8552
Total 9 13418.4
The regression equation is . Select one:
a. Ŷ = 2.1794 - 12.8094 X
b. Ŷ = -12.80894 + 2.1794X
c. 12.8094 X = 2.1794 Ŷ
d. X = -12.8094 + 2.1794 Ŷ
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The correct answer is: Ŷ = -12.80894 + 2.1794X
Question 22
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A sales manager for an advertising agency believes that there is a relationship between the number of contacts that a salesperson makes and the amount of sales dollars earned.
A regression analysis shows the following results:
Coefficients Standard
t-Stat p-value
What is the decision regarding the hypothesis that the slope equals zero? Select one:
a. Fail to reject the null hypothesis.
b. Fail to reject the alternative hypothesis.
c. Reject the null hypothesis.
d. Reject the alternative hypothesis.
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The correct answer is: Reject the null hypothesis.
Question 23
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What is the test statistic to test the significance of the slope in a regression equation? Select one:
a. z-statistic
b. F-statistic
c. t-statistic
d. π-statistic
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The correct answer is: t-statistic
Question 24
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The regression equation is Ŷ = 30 + 2.56X, the sample size is 14, and the standard error of the slope is 0.97. What is the test-statistic to test the significance of the slope?
Select one:
a. z = -2.560
b. z = +2.639
c. t = +2.560
d. t = +2.639
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The correct answer is: t = +2.639
Question 25
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Using the following information:
Coefficients
Intercept -12.8094
Independent Variable 2.1794
ANOVA
df SS MS F
Regression 1 12323.56 12323.56 90.0481
Residual 8 1094.842 136.8552
Total 9 13418.4
The regression analysis can be summarized as follows:
Select one:
a. No significant relationship between the variables.
b. A significant negative relationship exists between the variables.
c. A significant positive relationship exists between the variables.
d. For every unit increase in X, Y decreases by 12.8094.
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The correct answer is: A significant positive relationship exists between the variables. [Show Less]