The mean annual incomes of certified welders are normally distributed with the mean
of $50,000 and a standard deviation of $2,000. The ship building association wishes to
find out whether their welders earn more or less than $50,000 annually. The alternate
hypothesis is that the mean is not $50,000. If the level of significance is 0.10, what is
the critical value?
A. +1.645
B. -1.282
C. 1.282
D. 1.645
Besides a payoff table, the information for decision analysis can be organized using a:
A. decision tree.
B. scatter diagram.
C. fishbone diagram.
D. Pareto chart.
Refer to the following distribution:
What is the class midpoint for the $45 up to $55 class?
A. 49
B. 49.5
C. 50
D. 50.5
A binomial distribution has 100 trials (n = 100) with a probability of success of 0.25 (Ï€
= 0.25). We would like to find the probability of 34 or more successes using the normal
distribution to approximate the binomial. Applying the continuity correction factor,
what z-score should be used?
A. 2.079
B. 2.194
C. 1.963
D. 0.25
A bank wishes to estimate the mean credit card balance owed by its customers. The
population standard deviation is estimated to be $300. If a 98% confidence interval is
used and an interval of $75 is desired, how many customers should be sampled?
A. 44
B. 212
C. 629
D. 87
A large restaurant contracts with a local laundry to wash white napkins. The laundry
returns the napkins in bundles of 100 napkins. The restaurant uses a sampling plan to
make a decision to use the bundle of napkins or return the bundle to the laundry. The
sampling plan uses a sample size of ten with a “number of rejects allowed” of one. If
the number of dirty napkins in a sample of ten is two, what decision is made?
A. The sample of ten is returned to the laundry.
B. The bundle is returned to the laundry.
C. The bundle is accepted and used.
D. The good napkins from the sample are kept.
As the sample size for a t distribution increases, the differences between the t
distribution and the standard normal distribution:
A. are unchanged and remain the same.
B. become smaller, as the t distribution approaches the standard normal distribution.
C. become greater.
D. are evident because the tails of the t distribution become thicker.
All other things being held constant, what is the change in the dependent variable for a
unit change in X1 for the multiple regression equation: Ŷ = 5.2 + 6.3X1 – 7.1 X2?
A. -7.1
B. +6.3
C. +5.2
D. +4.4
Management is considering a bonus system to increase production. One suggestion is to
pay a bonus on the highest 5% of production based on past experience. Past records
indicate that an average of 4,000 units of a small assembly is produced during a week.
The distribution of the weekly production is approximately normally distributed with a
standard deviation of 60 units. If the bonus is paid on the upper 5% of production, the
bonus will be paid on how many units or more?
A. 6255
B. 5120
C. 3196
D. 4099
The results of a mathematics placement exam at two different campuses of Mercy
College follow:
Given that the two population standard deviations are known, what is the p-value?
A. 1.0
B. 0.0
C. 0.05
D. 0.95
Which of the following is NOT a component of the decision-making process?
A. Alternatives
B. Payoff
C. States of nature
D. Seasonal indexes
A personnel manager is concerned about absenteeism. She decides to sample employee
records to determine if absenteeism is distributed evenly throughout the six-day
workweek. The null hypothesis is: Absenteeism is distributed evenly throughout the
week. The 0.01 level is to be used. The sample results are:
What is the expected frequency?
A. 9
B. 10
C. 11
D. 12
A random sample of 400 families who planned to buy a vacation residence revealed that
228 families want to buy a condominium in Florida. At the 0.01 significance level, test
the statement that 55% of those families who plan to purchase a vacation residence in
Florida want a condominium. To decide if the sample data support the 55%, state your
decision in terms of the null hypothesis. Use a 0.01 level of significance.
If the exports (in $millions) for the period 2006 through 2010 were $878, $892, $864,
$870, and $912, respectively, what are these values called?
A. Moving average
B. Linear trend equation
C. Logarithmic trend equation
D. Time series data
Which of the following statements is correct regarding the goodness-of-fit test?
A. Variables are based on the nominal measurement scale.
B. Population must be normal.
C. All the expected frequencies must be equal.
D. All the expected frequencies must be unequal.
The following are the ratings (0 to 4) given by 12 individuals for two possible new
flavors of soft drinks.
Wilcoxon rank-sum is to be used.
What is the z test statistic?
A. -0.3464
B. 0.3464
C. 8.6602
D. 0.2807
When statisticians analyze sample data in order to draw conclusions about the
characteristics of a population, this is referred to as:
A. Descriptive statistics
B. Statistical inference
C. Data analysis
D. Data summarization
A hypothesis regarding the weight of newborn infants at a community hospital is that
the mean is 6.6 pounds. A sample of seven infants is randomly selected and their
weights at birth are recorded as 9.0, 7.3, 6.0, 8.8, 6.8, 8.4, and 6.6 pounds. What is the
sample standard deviation?
A. 1.177
B. 1.188
C. 1.386
D. 1.090
The CPI for “personal computers and peripheral equipment” in June 2006 was 10.7
(1982-1984 = 100). Interpret this index.
A. There was no significant increase in the price of “personal computers and peripheral
equipment.”
B. The price of “personal computers and peripheral equipment” increased 10.7%.
C. The price of “personal computers and peripheral equipment” decreased 89.3%.
D. If the average price of a computer in 1982-1984 was $3,000, the CPI for “personal
computers and peripheral equipment” would predict that the price of a computer in June
2006 would be $893.
Refer to the following breakdown of responses to a survey of room service in a hotel.
What percent of the responses indicated that customers were satisfied?
A. 40%
B. 33%
C. 50%
D. 100%
The chi-square statistic _______________.
A. Is greater than or equal to zero
B. Is less than or equal to zero
C. Can be any value
D. Is equal to zero
For a chi-square test involving a contingency table, suppose the null hypothesis is
rejected. We conclude that the two variables are __________.
A. Linear
B. Curvilinear
C. Not related
D. Related
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:
When comparing the mean annual dividend rate for companies in the utilities and
insurance industries, which of the following 95% confidence interval can be
constructed?
A. 5.78 2.160 * 2.40
B. 5.78 2.120 * 2.40
C. 5.78 2.160 * 1.11
D. 5.78 2.120 * 1.11
This nonparametric test requires at least ordinal level data. t is used if the assumptions
required for the paired t test cannot be met. Which test is it?
A. Wilcoxon signed-rank test
B. ANOVA
C. Rank correlation
D. Kruskal-Wallis
The square root of the variance is called the ______.
In a contingency table, the decision to reject the null hypothesis is based on a
__________ test statistic.
What is the advantage of using ANOVA to test for differences among treatment means
rather than testing all possible pairs of treatment means?
We are interested in knowing if the following frequency distribution is normally
distributed. The population mean and standard deviation of the data are 600 and 160,
respectively.
If the distribution was normally distributed, what is the expected frequency for the “400
up to 600″ class?
The coefficient of skewness measures a distribution’s ____________ symmetry.
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 value of the test statistic?
Cook County public safety monitors the number of “driving under the influence” arrests
and is interested in the distribution of arrests in the month of December over the last
five years. The data are shown next.
What is the sample variance?
In a survey of employee satisfaction, the following table summarizes the results in
terms of employee satisfaction and gender.
What is the probability that an employee is male or dissatisfied?
A __________ shows the interquartile range.