A standard normal distribution is a normal distribution with
a. a mean of 1 and a standard deviation of 0
b. a mean of 0 and a standard deviation of 1
c. any mean and a standard deviation of 1
d. any mean and any standard deviation
Exhibit 10-13
In order to determine whether or not there is a significant difference between the hourly
wages of two companies, the following data have been accumulated.
Refer to Exhibit 10-13. The p-value is
a.
b.
c.
d.
Information regarding the ACT scores of samples of students in three different majors
are given below.
A method of smoothing a time series that can be used to identify the combined
trend/cyclical component is
a. the moving average
b. the percent of trend
c. exponential smoothing
d. the trend/cyclical index
The expected value of the random variable is
a.
b. the standard error
c. the sample size
d.
Exhibit 15-5
Below you are given a partial Excel output based on a sample of 25 observations.
Refer to Exhibit 15-5. The t value obtained from the table to test an individual
parameter at the 5% level is
a. 2.06
b. 2.069
c. 2.074
d. 2.080
Zip, Inc. manufactures Zip drives on two different manufacturing processes. Because
the management of this company is interested in determining if process 1 takes less
manufacturing time, they selected independent samples from each process. The results
of the samples are shown below.
a. State the null and alternative hypotheses.
b. Determine the degrees of freedom for the t test.
c. Compute the test statistic
d. At 95% confidence, test to determine if there is sufficient evidence to indicate that
process 1 takes a significantly shorter time to manufacture the Zip drives.
A survey of business students who had taken the Graduate Management Admission Test
(GMAT) indicated that students who have spent at least five hours studying GMAT
review guides have a probability of 0.85 of scoring above 400. Students who do not
spend at least five hours reviewing have a probability of 0.65 of scoring above 400. It
has been determined that 70% of the business students spent at least five hours
reviewing for the test.
For the Excel worksheet above, which of the following formulas would correctly
calculate the posterior probability for cell E3?
a. =SUM(B3:D3)
b. =D3/$D$5
c. =D5/$D$3
d. B3/C3+D3
Exhibit 3-1
A researcher has collected the following sample data.
Refer to Exhibit 3-1. The median is
a. 5
b. 6
c. 7
d. 8
Delta Corp’s plant in Austin has been experiencing imbalances in its inventory of
components used in the production of a line of computer printers. Both stock shortages
and overstock conditions are occurring.
The production analysis group is studying the pattern of demand for component
PS2400, a power supply used in many of Delta’s products. The group believes that the
most recent 12 weeks of demand for the PS2400 is representative of the future weekly
demand:
a. Use a four-week moving average to develop a forecast of the demand for the PS2400
component in week 13.
b. Use a four-week weighted moving average with weights of .4 (for the most recent
datum), .3, .2, and .1 to forecast the demand for the PS2400 component in week 13.
Exhibit 13-5
Part of an ANOVA table is shown below.
Refer to Exhibit 13-5. The conclusion of the test is that the means
a. are equal to fifty
b. may be equal
c. are not equal
d. None of these alternatives is correct.
Which of the following is an example of nonprobabilistic sampling?
a. simple random sampling
b. stratified simple random sampling
c. cluster sampling
d. judgment sampling
The weight of an object, measured in grams, is an example of
a. a continuous random variable
b. a discrete random variable
c. either a continuous or a discrete random variable, depending on the weight of the
object
d. either a continuous or a discrete random variable depending on the units of
measurement
Z is a standard normal random variable. What is the value of z if the area between –z
and z is 0.754?
a. 0.377
b. 0.123
c. 2.16
d. 1.16