If autocorrelation occurs in regression analysis, then the confidence intervals and tests
using the t and F distributions are no longer strictly applicable.
Variables which take on values only at certain points over a given interval are called
continuous random variables
Regression output from Minitab software includes an ANOVA table.
The appropriate test for comparing the means of two populations using ordinal-level
data from two related samples is the Wilcoxon test and not the Mann-Whitney Utest.
The F value that is used to test for the overall significance of a multiple regression
model is calculated by dividing the mean square regression (MSreg) by the mean square
error (MSerr).
The nonparametric counterpart of the ttest to compare the means of two independent
populations is the Mann-Whitney Utest.
When the population standard deviation, , is unknown the sample standard
deviation, s, is used in determining the interval estimate for the population mean.
If a null hypothesis was not rejected at the 0.10 level of significance, it will be rejected
at a 0.05 level of significance based on the same sample results.
Assigning probabilities by dividing the number of ways that an event can occur by the
total number of possible outcomes in an experiment is called the classical method.
For a company in gardening supplies business, the best graphical way to show the
percentage of a total budget that is spent on each of a number of different expense
categories is the stem and leaf plot.
In a decision analysis problem, variables (such as investing in common stocks or
corporate bonds) which are under the decision maker’s control are called decision
alternatives.
The Poisson distribution is a continuous distribution which is very useful in solving
waiting time problems
If the population is normal and its standard deviation, , is known but the
sample size is small, z-distribution values may not be used to determine interval
estimates for the population mean.
One of the main techniques for isolating the effects of seasonality is reconstitution.
The standard error of the estimate of a multiple regression model is essentially the
standard deviation of the residuals for the regression model.
The expected monetary payoff of perfect information is the value of perfect
information.
The assumption of independent trials in a binomial distribution is not a great concern if
the sample size is smaller than 1/20th of the population size.
A standard normal distribution has a mean of one and a standard deviation of three.
Analysis of variance may be used to test the differences in the means of more than two
independent populations.
The F test is used to determine whether the overall regression model is significant.
The null hypothesis in a chi-square goodness-of-fit test is that the observed distribution
is the same as the expected distribution.
Nonparametric statistics are sometimes called distribution-dependent statistics.
The statistical methods of analysis of variance assume that the populations are normally
distributed.
One rule that must always be followed in constructing frequency distributions is that the
adjacent classes must overlap.
If a data set contains k independent variables, the “all possible regression” search
procedure will determine 2k” 1 different models.
Spearman rank correlation values, rx, range between +1 and 0.
No assumptions on the distribution of the difference are needed for the use of the
Wilcoxon matched-pairs signed rank.
The degree of association of two variables cannot be estimated when only ordinal-level
data are available.
Binomial distributions in which the sample sizes are large may be approximated by a
Poisson distribution.
Regression output from Minitab software directly displays the
regression equation.
The strength of a linear relationship in simple linear regression change if the units of the
data are converted, say from feet to inches.
If the populations are normally distributed but the population variances are unknown
the t-statistic can be used as the basis for statistical inferences about the difference in
two population means using two independent random samples.
An experiment is a process that produces outcomes.
If each pair of independent variables is weakly correlated, there is no problem of
multicollinearity.
Power is equal to (1 “), the probability of a test rejecting the null hypothesis that is
indeed false.
Six Sigma is a methodology for quality and does not relate to a measurement value of
the process.
The sum of deviations about the arithmetic mean is always equal to zero.
The following graph is a binomial distribution withn = 6.
This graph reveals that ____________.
a) p > 0.5
b) p = 1.0
c) p = 0
d) p < 0.5
e) p = 1.5
An “all possible regressions” search of a data set containing 7 independent variables
will produce ______ regressions.
a) 13
b) 127
c) 48
d) 64
e) 97
You are conducting a study on the blood glucose levels of 9 patients who are on strict
diets and exercise routines. To monitor the mean and range of the blood glucose levels
of your patients, you take a blood glucose reading every day for each patient for 20
days. The results are shown below.
The centerline for your chart is _________.
a) 112.70
b) 106.7
c) 101.035
d) 100
e) 110
A manager wants to predict the cost (y) of travel for salespeople based on the number of
days (x) spent on each sales trip. The following model has been developed: y = $400 +
120x. If a trip took 4 days, the predicted cost of the trip is _____________.
a) 480
b) 880
c) 524
d) 2080
e) 1080
A multiple regression analysis produced the following tables.
The coefficient of multiple determination is ____________.
a) 0.0592
b) 0.9138
c) 0.1149
d) 0.9559
e) 1.0000
A carload of palletized aluminum castings has arrived at Mansfield Motor
Manufacturers. The car contains 1,000 pallets of 100 castings each. Mario Munoz,
manager of Quality Assurance, directs the receiving crew to deliver the 127th and 869th
pallets to his crew for 100% inspection. Mario randomly selected 127 and 869 from a
table of random numbers. Mario’s sample of 200 castings is a _____________.
a) simple random sample
b) systematic sample
c) stratified sample
d) cluster sample
e) convenience sample
Participants in a 2 day biking event, cross the finish line at a rate of 10 bike riders per
fifteen minute interval. The probability that less than 10 minutes will elapse between
car arrivals is _____________.
a) .0001
b) .9987
c) .0013
d) .6667
e) .1667
Maureen McIlvoy, owner and CEO of a mail order business for wind surfing equipment
and supplies, is reviewing the order filling operations at her warehouses. Her goal is
100% of orders shipped within 24 hours. In previous years, neither warehouse has
achieved the goal, but the East Coast Warehouse has consistently out-performed the
West Coast Warehouse. Her staff randomly selected 200 orders from the West Coast
Warehouse (population 1) and 400 orders from the East Coast Warehouse (population
2), and reports that 190 of the West Coast Orders were shipped within 24 hours, and the
East Coast Warehouse shipped 356 orders within 24 hours. Assuming
= 0.05, the
appropriate decision is ___________________.
a) reject the null hypothesis p1” p2= 0
b) reject the null hypothesis 1– 2<0
c) do not reject the null hypothesis 1– 2= 0
d) do not reject the null hypothesis p1” p2= 0
e) do not reject the null hypothesis p1” p2≥0
A multiple regression analysis produced the following tables.
The sample size for this analysis is ____________.
a) 12
b) 15
c) 17
d) 18
e) 24
For a certain data set the regression equation is y = 29 – 5x. The correlation coefficient
between y and x in this data set _______.
a) must be 0
b) is negative
c) must be 1
d) is positive
e) must be >1
Maureen McIlvoy, owner and CEO of a mail order business for wind surfing equipment
and supplies, is reviewing the order filling operations at her warehouses. Her goal is
100% of orders shipped within 24 hours. In previous years, neither warehouse has
achieved the goal, but the East Coast Warehouse has consistently out-performed the
West Coast Warehouse. Her staff randomly selected 200 orders from the West Coast
Warehouse (population 1) and 400 orders from the East Coast Warehouse (population
2), and reports that 190 of the West Coast Orders were shipped within 24 hours, and the
East Coast Warehouse shipped 372 orders within 24 hours. Maureen’s null hypothesis is
____.
a) p1” p2= 0
b) 1– 2= 0
c) p1” p2>0
d) 1– 2<0
e) 1– 2≥0
In the regression equation, y = 49.56 + 0.97x, the slope is _______.
a) 0.97
b) 49.56
c) 1.00
d) 0.00
e) -0.97
The normal distribution is an example of _______.
a) a discrete distribution
b) a continuous distribution
c) a bimodal distribution
d) an exponential distribution
e) a binomial distribution
Paige DeMarco is the Vice President for University Advancement at State University.
She is responsible for the capital campaign to raise money for the new student services
building. Paige plans to target alumni and acquires her sampling frame from the State
University Office of Alumni Relations. She intends to contact these individuals
regarding possible donations. She randomly selects the sixth name as a starting point
and then selects every 100th subsequent name (106, 206, 306, etc.). Her sample is a
_________.
a) simple random sample
b) stratified sample
c) systematic sample
d) convenience sample
e) cluster sample
The table below provides summary information about students in a class. The sex of
each individual and their age is given.
If a student is randomly selected from this group, what is the probability that the student
is male?
a) 0.12
b) 0.48
c) 0.50
d) 0.52
e) 0.68
David Desreumaux, VP of Human Resources of American First Banks (AFB), is
reviewing the employee training programs of AFB banks. His staff reports several
statistics for teller training hours. The mean is 20 hours, the standard deviation is 5
hours, the median is 15 hours, and mode is 10 hours. The Pearsonian coefficient of
skewness for teller training hours is __________.
a) 6
b) 1
c) 3
d) 4
e) 0
Unweighted price indexes compare across the entire time period for which there is data.
Abby Kratz, a market specialist at the market research firm of Saez, Sikes, and Spitz, is
analyzing household budget data collected by her firm. Abby’s dependent variable is
weekly household expenditures on groceries (in $’s), and her independent variables are
annual household income (in $1,000’s) and household neighborhood (0 = suburban, 1 =
rural). Regression analysis of the data yielded the following table.
For two households, one suburban and one rural, Abby’s model predicts ________.
a) equal weekly expenditures for groceries
b) the suburban household’s weekly expenditures for groceries will be $49 more
c) the rural household’s weekly expenditures for groceries will be $49 more
d) the suburban household’s weekly expenditures for groceries will be $8 more
e) the rural household’s weekly expenditures for groceries will be $49 less
A small restaurant owner believes exactly 36 % of his customers come to the restaurant
because of his daily half-price specials. He is interested in expanding his daily specials
and increasing the price. However, he would like to test his hypothesis prior to
expanding the daily special offerings. He intends to use the following null and
alternative hypotheses.
Ho: p= 0.36
Ha: p 0.36
These hypotheses _______________.
a) indicate a one-tailed test with a rejection area in the right tail
b) indicate a one-tailed test with a rejection area in the left tail
c) indicate a two-tailed test
d) are established incorrectly
e) are not mutually exclusive
Medical Wonders is a specialized interior design company focused on healing artwork.
The CEO, Kathleen Kelledy claims that artwork has healing effects for patients staying
in a hospital, as measured by reduced length of stay. Her current client is a children’s
cancer hospital. Kathleen is interested in determining the effect of three different pieces
of healing artwork on children. She chooses three paintings (a horse photo, a bright
abstract, and a muted beach scene) and randomly assigns six hospital rooms to each
painting. Kathleen’s experimental design is a ________.
a) factorial design
b) random block design
c) normalized block design
d) completely randomized design
e) fractional design
Belinda Bose is reviewing a newly proposed advertising campaign. Based on her
15-years’ experience, she believes the campaign has a 75% chance of significantly
increasing brand name recognition of the product. This is an example of assigning
probabilities using the ________________ method.
a) subjective probability
b) relative frequency
c) classical probability
d) a priori probability
e) a posterior probability
Let zbe a normal random variable with mean 0 and standard deviation 1. What is P(z>
-1.1)?
a) 0.36432
b) 0.8643
c) 0.1357
d) -0.1357
e) -0.8643
Lucy Baker is analyzing demographic characteristics of two television programs,
American Idol(population 1) and 60 Minutes (population 2). Previous studies indicate
no difference in the ages of the two audiences. (The mean age of each audience is the
same.) Her staff randomly selected 100 people from each audience, and reported the
following: 1= 43 years and 2= 45 years. Assume that 1= 5 and 2=
8. With a two-tail test and a= .05, the critical zvalues are _________________.
a) -1.64 and 1.64
b) -1.96 and 1.96
c) -2.33 and 2.33
d) -2.58 and 2.58
e) -2.97 and 2.97
Pinky Bauer, Chief Financial Officer of Harrison Haulers, Inc., suspects irregularities in
the payroll system, and orders an inspection of a random sample of vouchers issued
since January 1, 2006. A sample of ten vouchers is randomly selected, without
replacement, from the population of 2,000 vouchers. Each voucher in the sample is
examined for errors and the number of vouchers in the sample with errors is denoted by
x. If 20% of the population of vouchers contains errors, the standard deviation of x is
______.
a) 1.26
b) 1.60
c) 14.14
d) 3.16
e) 0.00
Meagan Dubean manages a portfolio of 200 common stocks. Her staff classified the
portfolio stocks by ‘industry sector’ and ‘investment objective.’
If a stock is selected randomly from Meagan’s portfolio, P (Airlines|Income) =
_______.
a) 0.10
b) 0.40
c) 0.25
d) 0.67
e) 0.90
The table t value associated with the upper 5% of the t distribution and 12 degrees of
freedom is _______.
a) 2.179
b) 1.782
c) 1.356
d) 3.055
e) 3.330
The Kruskal-Wallis test is to be used to determine whether there is a significant
difference in the satisfaction rating (alpha = 0.05) between three brands of boxed cake
mix. Shoppers were asked to rate their satisfaction on various attributes and an
aggregate satisfaction score ranging from 1-50 was computed. The following data were
obtained:
For this situation, the critical (table) chi-square value is _______.
a) 15.507
b) 7.815
c) 9.488
d) 5.991
e) 3.991
Maureen McIlvoy, owner and CEO of a mail order business for wind surfing equipment
and supplies, is reviewing the order filling operations at her warehouses. Her goal is
100% of orders shipped within 24 hours. In previous years, neither warehouse has
achieved the goal, but the East Coast Warehouse has consistently out-performed the
West Coast Warehouse. Her staff randomly selected 200 orders from the West Coast
Warehouse (population 1) and 400 orders from the East Coast Warehouse (population
2), and reports that 190 of the West Coast Orders were shipped within 24 hours, and the
East Coast Warehouse shipped 372 orders within 24 hours. Assuming
= 0.05, the
appropriate decision is ___________________.
a) do not reject the null hypothesis 1– 2= 0
b) do not reject the null hypothesis p1” p2= 0
c) reject the null hypothesis 1– 2= 0
d) reject the null hypothesis p1” p2= 0
e) do not reject the null hypothesis p1” p2≥0
The following is a bar chart of the self-reported race for 189 pregnant women.
Approximately _____ percent of pregnant women are African-American
a) 20
b) 14
c) 5
d) 35
e) 50
A researcher wants to conduct a before/after study on 11 subjects to determine if a new
cholesterol medication results in higher HDL cholesterol readings. The null hypothesis
is that the average difference is zero while the alternative hypothesis is that the average
difference is not zero. Scores are obtained on the subjects both before and after taking
the medication. After subtracting the after scores from the before scores, the average
difference is computed to be “2.40 with a sample standard deviation of 1.21. Assume
that the differences are normally distributed in the population. The degrees of freedom
for this test are _______.
a) 11
b) 10
c) 9
d) 20
e) 2
Data from a randomized block design are shown in the following table.
Using
= 0.05, the appropriate decision for the blocking effects is ________.
a) reject the null hypothesis
1
2
3
b) do not reject the null hypothesis
1
2
3
c) do not reject the null hypothesis
d) reject the null hypothesis
1
2
3
e) do nothing
Data from a completely randomized design are shown in the following table.
For a one-way ANOVA, the Error Sum of Squares (SSE) is ________.
a) 36.17
b) 28.75
c) 64.92
d) 18.03
e) 28.04
The net profit from a certain investment is normally distributed with a mean of $2,500
and a standard deviation of $1,000. The probability that the investor will not have a net
loss is _____________.
a) 0.4938
b) 0.0062
c) 0.9938
d) 0.5062
e) 0.0000