In: Statistics and Probability
Question 35
A professor in the Accountancy Department of a business school
indicated that there is much more variability in the final exam
scores of students taking the introductory accounting course as a
requirement than for students taking the course as part of their
major. Random samples of 16 non-accounting majors and 10 accounting
majors taken from the professor's class roster in his large lecture
and the following results are computed based on the final exam
scores:
Non-Accounting Major (1) |
Accounting Major (2) |
n=16 |
n=10 |
S2 = 210.2 |
S2 = 36.5 |
Using =5%, the test and critical F-values, for the hypothesis test to support the professor's statement, respectively are:
Select one:
a. 5.7589 and 3.77 respectively
b. 0.1736 and 3.77 respectively
c. 5.7589 and 3.01 respectively
d. 2.3998 and 3.01 respectively
Question 42
An electrical engineer is interested in the effect on the tube conductivity of five different types of coating for cathode ray tubes used in telecommunications system display device. The following conductivity data are obtained:
Coating Type
1 143 141 150 146
2 152 149 137 143
3 134 133 132 127
4 129 127 132 129
5 147 148 144 142
At 5% level of significance, is there any difference in conductivity due to coating type? What is the value of test statistic?
Select one:
a. 16.35
b. 19.0
c. 15
d. 3.06
Question 43
Last school year, the student body of a local university
consisted of 30% freshmen, 24% sophomores, 26% juniors, and 20%
seniors. A sample of 400 students taken from this year's student
body showed the following number of students in each
classification.
Freshmen | 113 |
Sophomores | 98 |
Juniors | 115 |
Seniors | 74 |
We are interested in determining whether or not there has been a significant change in the classifications between the last school year and this school year. The calculated value for the test statistic equals
Select one:
a. .54.
b. .65.
c. 2.063.
d. 2.664.
Question 46
An electric company operates a fleet of trucks that provide electrical service to the construction industry. Monthly maintenance cost has been $75 per truck. A random sample of 16 trucks provided a sample mean maintenance cost of $82.50 per month, with a sample standard deviation of $30. Using a 5% level of significance, you like to see whether the mean monthly maintenance cost has increased. Set the appropriate hypotheses and calculate the test statistic
Select one:
a. Z = +/- 1.0
b. t = +/-1.0
c. Z = 1.0
d. t = 1.0