A manufacturer of automobile transmissions uses three different processes.
Management ordered a study of the production costs to see if there is a difference
among the three processes. A summary of the findings is shown next.
In an ANOVA table, what are the total degrees of freedom?
A. 27
B. 28
C. 29
D. 30
A stockbroker placed the following order for a customer:
‘¢ 50 shares of Kaiser Aluminum at $104 a share
‘¢ 100 shares of GTE at $25.25 a share
‘¢ 20 shares of Boston Edison at $9.125 a share
What is the weighted arithmetic mean price per share?
A. $25.25
B. $79.75
C. $103.50
D. $46.51
What is the decision regarding the differences between the observed and expected
frequencies if the critical value of chi-square is 9.488 and the computed chi-square
value is 6.079?
A. Fail to reject the null hypothesis; the difference is probably due to sampling error.
B. Reject the null hypothesis.
C. Fail to reject the alternate hypothesis.
D. Too close; reserve judgment.
The college of business was interested in comparing the attendance for three different
class times for a business statistics class. The data follow.
What is the critical F statistic for testing the hypothesis of equal treatment means at the
0.05 significance level?
A. 1.96
B. 6.94
C. 3.84
D. 4.46
What time series component was exemplified during the 1980s when the American
economy enjoyed a period of prosperity?
A. Irregular
B. Cyclical
C. Trend
D. Seasonal
A national manufacturer of unattached garages discovered that the distribution of the
time for two construction workers to erect the Red Barn model is normally distributed
with a mean of 32 hours and a standard deviation of 2 hours. What percent of the
garages take between 32 and 34 hours to erect?
A. 16.29%
B. 76.71%
C. 3.14%
D. 34.13%
Sampling error is the difference between a sample statistic and its corresponding
_________.
A. Sample mean
B. Variance
C. Population parameter
D. Trend
In multiple regression analysis, how is the degree of association between a set of
independent variables and a dependent variable measured?
A. Confidence intervals
B. Autocorrelation
C. Coefficient of multiple determination
D. Standard error of estimate
The decision rule for a small sample sign test is based on a(n):
A. binomial distribution.
B. chi-square distribution.
C. normal distribution.
D. F distribution.
The range of the coefficient of skewness is ____________.
A. Values greater than or equal to zero or always positive
B. Values less than or equal to zero or always negative
C. Both positive and negative values
D. Values between -1 and +1
What is usually developed to evaluate a sampling plan?
A. Frequency polygon
B. Scatter diagram
C. Operating characteristic curve
D. Simple bar chart
The z-score or z-value corresponding to a 95.34% confidence interval is ________.
A. 1.96
B. 1.65
C. 1.99
D. 1.68
When testing for differences between treatment means, the degrees of freedom for the t
statistic are ___________.
A. k
B. (n – 1)
C. (n – k)
D. (1/n1 + 1/n2)
In a time series, economic periods of prosperity followed by recession are described as
a(n) ___________.
A. secular trend
B. seasonal variation
C. cyclical variation
D. erratic variation
How is the t distribution similar to the standard z distribution?
A. Both are discrete distributions.
B. Both are skewed distributions.
C. Both are families of distributions.
D. Both are continuous distributions.
A measure of the long-run average value of a random variable used to represent the
central location of a probability distribution is called a(n) _____________.
A. population variance
B. population standard deviation
C. expected value
D. coefficient of variation
The national sales manager for “I colored this” (ICT) T-shirts provides all salespersons
with the payoff table shown next, giving the estimated profit when a retailer purchases
from one to four dozen T-shirts. The probability of demand for each state of nature is
also shown.
What would be the best decision if the maximax strategy is used?
A. 1
B. 2
C. 3
D. 4
Based on the Nielsen ratings, the local CBS affiliate claims its 11 p.m. newscast reaches
41% of the viewing audience in the area. In a survey of 100 viewers, 36% indicated that
they watch the late evening news on this local CBS station. What is your decision if α
= 0.01?
A. Fail to reject the null hypothesis.
B. Reject the null hypothesis and conclude the newscast does not reach 41% of the
audience.
C. Fail to reject the alternate and conclude the newscast does not reach 41% of the
audience.
D. Reject the alternate and conclude the newscast reaches about 41% of the audience.
In a distribution, the second quartile corresponds with the __________.
A. Mean
B. Median
C. Mode
D. Variance
A company is researching the effectiveness of a new website design to decrease the
time to access a website. Five website users were randomly selected, and their times (in
seconds) to access the website with the old and new designs were recorded. To compare
the times, they computed (new website design time – old website design time). The
results follow.
For a 0.01 significance level, what is the decision regarding the hypothesis that the
training was effective in improving customer relationships?
A. Reject the null hypothesis and conclude that the new design reduced the mean access
times.
B. Reject the null hypothesis and conclude that the new design did not reduce the mean
access times.
C. Fail to reject the null hypothesis.
D. Fail to reject the null hypothesis and conclude that the mean access times are
inaccurate.
Which of the following is NOT necessary to determine how large a sample to select
from a population?
A. The level of confidence in estimating the population parameter
B. The size of the population
C. The maximum allowable error in estimating the population parameter
D. An estimate of the population variation
What is another name for the alternate hypothesis?
A. Null hypothesis
B. Hypothesis of no difference
C. Rejected hypothesis
D. Research hypothesis
The following table shows the sales for a resort hotel recorded over the past year. The
seasonal indexes for each quarter are also provided. To track the trend for these four
quarters, use the indexes to deseasonalize the sales data.
What is the deseasonalized sales value for quarter 3?
When independent samples with unknown but equal standard deviations are used to test
for differences in the means, we pool the sample _________________.
The collection of all possible objects of interest is referred to as the ____________.
In practice, researchers collect a sample of size “n” and compute point estimates of
population parameters. How can sampling error be reduced?
To compare the effect of weather on sales of soft drinks, a distributor surveyed people
in two regions of the country and asked if they purchased soft drinks in the last month.
The following are the results. The distributor would like to know if there is a difference
in sales between the two regions.
What is the pooled estimate of the population proportion?
The branch of statistics that collects, analyzes, and presents data is called
_____________ statistics.