The mean of a binomial distribution is the product of n and π.
The variance of a binomial distribution is found by nÏ€(1 – Ï€).
The “box” in a box plot shows the interquartile range.
If the time series trend is non-linear, a transformation of the data is required.
Statistics are used as a basis for making decisions.
When referring to the normal probability distribution, there is not just one; there is a
“family” of normal probability distributions.
A Spearman’s rank-order correlation coefficient of 0.91 indicates a very weak
relationship.
The finite population correction factor is applied when the population size is known.
A population consists of the following four values: 8, 10, 12, and 16. From this
population, there are six different samples of size 2. The means of the six samples of
size 2 are 9, 10, 12, 11, 13, and 14. Compute the mean of the distribution of the sample
means and the population mean. What is
To employ ANOVA, the populations should have approximately equal standard
deviations.
Two normal distributions are compared. One has a mean of 10 and a standard deviation
of 10. The second normal distribution has a mean of 10 and a standard deviation of 2.
Which of the following is
The strength of the correlation between two variables depends on the sign of the
coefficient of correlation.
We can expect some difference between sample statistics and the corresponding
population parameters. This difference is called the sampling error.
A sampling distribution of the means is a probability distribution consisting of all
possible sample means of a given sample size selected from a population.
The complement rule states that the probability of an event not occurring is equal to one
minus the probability of its occurrence.
Given the following ANOVA table for three treatments each with six observations:
What are the degrees of freedom for the treatment and error sources of variation?
A. 3 and 18
B. 2 and 17
C. 3 and 15
D. 2 and 15
If the critical z value for a hypothesis test equals 2.45, what value of the test statistic
would provide the least chance of making a Type I error?
A. 3.74
B. 10,000
C. 2.46
D. 4.56
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 is the expected payoff for purchasing one dozen T-shirts?
A. 0
B. 72
C. 120
D. 168
Define the level of significance.
A. It is the probability of a Type II error.
B. It is the probability of a Type I error.
C. It is a z value of 1.96.
D. It is the beta error.
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. If α = 0.05,
what is the critical t value?
A. -2.365
B. 1.96
C. 2.365
D. 2.447
An analysis of the grades on the first test in History 101 revealed that they approximate
a normal curve with a mean of 75 and a standard deviation of 8. The instructor wants to
award the grade of A to the upper 10% of the test grades. To the nearest percent, what is
the dividing point between an A and a B grade?
A. 80
B. 85
C. 90
D. 95
A hypothesis test that rho is zero is conducted at the 5% level of significance. If
Spearman’s (rho) is 0.50 for a sample of 15 observations, what is the critical value?
A. 2.160
B. 2.131
C. 1.771
D. 1.753
An example of a way to rescale a variable to create a linear relationship is:
A. dividing all the values of the dependent variable by 5.
B. computing the log of all values of the dependent and independent variable.
C. adding 50 to all of the values of the dependent and independent variables.
D. adding the values of the dependent and independent variables to create a new
dependent variable.
If a sign test is applied, what is the null hypothesis for a two-tailed test?
A.
B.
C.
D.
Twenty-five college seniors were given two brands of organic hamburgers to sample:
Burger A and Burger B. Four students preferred Burger A and 21 preferred Burger B. A
statistician wants to determine if one of the burgers is preferred over the other.
The null hypothesis for this scenario is:
A. H0: μ = 5.0.
B. H0: μ = 5.0.
C. H0: μ = 0.5.
D. H0: μ = 0.5.
In an ANOVA table for a multiple regression analysis, the regression mean square is
__________.
A. The treatment sum of squares divided by the regression degrees of freedom
B. n – (k + 1)
C. The regression sum of squares divided by the regression degrees of freedom
D. The total sum of squares divided by the regression degrees of freedom
Given the following ANOVA table for three treatments each with six observations:
What is the computed value of F?
A. 7.48
B. 7.84
C. 8.84
D. 8.48
Multiple regression analysis is applied when analyzing the relationship between
__________.
A. An independent variable and several dependent variables
B. A dependent variable and several independent variables
C. Several dependent variables and several independent variables
D. Several regression equations and a single sample
Accounting procedures allow a business to evaluate its inventory costs based on two
methods: LIFO (Last In First Out) or FIFO (First In First Out). A manufacturer
evaluated its finished goods inventory (in $000s) for five products with the LIFO and
FIFO methods. To analyze the difference, they computed (FIFO – LIFO) for each
product. Based on the following results, does the LIFO method result in a lower cost of
inventory than the FIFO method?
What is the decision at the 5% level of significance?
A. Fail to reject the null hypothesis and conclude LIFO is more effective.
B. Reject the null hypothesis and conclude LIFO is more effective.
C. Reject the alternate hypothesis and conclude LIFO is more effective.
D. Fail to reject the null hypothesis.
For a time series beginning with 1991 and extending up to 2010, which year would be
coded with a one when using the coded method?
A. 1989
B. 1991
C. 1992
D. 2001
What is the relationship among the mean, median, and mode in a symmetric
distribution?
A. They are all equal.
B. The mean is always the smallest value.
C. The mean is always the largest value.
D. The mode is the largest value.
The best example of a null hypothesis for a global test of a multiple regression model is
_________.
A. H0: β1 = β2 = β3 = β4 = 0
B. H0: 1 = 2 = 3 = 4 = 0
C. H0: β1 = 0
D. If F is greater than 20.00, then reject
If a multiple regression analysis is based on 10 independent variables collected from a
sample of 125 observations, what is the value of the denominator in the calculation of
the multiple standard error of estimate?
A. 125
B. 10
C. 114
D. 115
Each salesperson in a large department store chain is rated on their sales ability and
their potential for advancement. The data for the 500 sampled salespeople are
summarized in the following table.
What is the probability that a salesperson selected at random will have average sales
ability and good potential for advancement?
A. 0.09
B. 0.12
C. 0.30
D. 0.525
The results of a mathematics placement exam at two different campuses of Mercy
College follow:
What is the computed value of the test statistic?
A. 9.30
B. 2.60
C. 3.37
D. 3.40
For an alternative hypothesis: > 6,700, where is the rejection region for the hypothesis
test located?
A. In both tails
B. In the left or lower tail
C. In the right or upper tail
D. In the center
Data for fuel oil and gasoline purchased at wholesale prices for 2006 and 2010 are
shown next.
What is Fisher’s ideal index?
A. 116.69
B. 179.08
C. 111.97
D. 109.36
A sales manager for an advertising agency believes there is a relationship between the
number of contacts that a salesperson makes and the amount of sales dollars earned.
A regression analysis shows the following results:
= 33.4. = 2814.4. Rounding to one decimal place, the 95%
confidence interval for 30 calls is ___________.
A. 55.8, 51.5
B. 51.4, 55.9
C. 46.7, 60.6
D. 31.1, 76.2
The 2009 CPI was 214.537 (1982-84 = 100). What is the purchasing power of the dollar
relative to the base?
The exponential distribution can be used to predict ________.
A major distributor buys shoes from a supplier. The distributor randomly samples the
shoes to inspect for quality. The distributor’s specifications state that a delivery of 100
pairs of shoes will be accepted only if the number of defective pairs of shoes in a
sample of 10 pairs is two or less. Based on the sampling plan, what is the probability of
accepting the delivery of 100 pairs of shoes if the actual percent defective is 0.05?
Elly’s Hotdog Emporium is famous for its chilidogs. Elly’s latest sales indicate that 30%
of the customers order their chilidogs with hot peppers. Suppose 15 customers are
selected at random. What is the probability that all 15 will want hot peppers?
A __________ clearly shows outliers.
For any probability distribution, the mean is calculated as a weighted mean. The
weights are the ______________.
In a uniform distribution, with a minimum, a, and maximum, b, the probability that the
random variable, x, is between a and b is ___________.
A university has 1,000 computers available for students to use. Each computer has a
250-gigabyte hard drive. The university wants to estimate the space occupied on the
hard drives. A random sample of 100 computers showed a mean of 115 gigabytes used
with a standard deviation of 20 gigabytes. What is the standard error of the mean?