For a normal distribution, what is the likelihood (expressed as a percentage) that a
random variable is within plus and minus two standard deviations of the mean?
A. 68.26%
B. 99.74%
C. 34.13%
D. 95.44%
The following partial ANOVA table was derived from data having four treatments and a
total of 16 observations.
The mean square between treatments (MST) is _______.
A. 85.33
B. 22.40
C. 48.00
D. 64.00
In hypothesis testing, what is the level of significance?
A. The risk of rejecting the null hypothesis when it is
TRUE.
B. A value symbolized by the Greek letter α.
C. A value between 0 and 1.
D. It is selected before a decision rule can be formulated.
E. All apply.
A sample of 250 adults tried the new multigrain cereal “Wow!” A total of 187 rated it as
excellent. In a sample of 100 children, 66 rated it as excellent. Using the 0.1
significance level, the researcher wishes to show that adults like the cereal better than
children. What test statistic should we use to compare the ratings of adults and
children?
A. A z-statistic
B. A right one-tailed test statistic
C. A left one-tailed test statistic
D. A t-statistic
In a large metropolitan area, past records revealed that 30% of all the high school
graduates go to college. From 20 graduates selected at random, what is the probability
that exactly 8 will go to college?
A. 0.114
B. 0.887
C. 0.400
D. 0.231
The number of employees less than the upper limit of each class at Lloyd’s Fast Food
Emporium is shown in the following table:
What is it called?
A. A histogram
B. A cumulative frequency table
C. A pie chart
D. A frequency polygon
The following correlations were computed as part of a multiple regression analysis that
used education, job, and age to predict income.
Which is the dependent variable?
A. Income
B. Age
C. Education
D. Job
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 the critical value if
the level of significance is 0.10?
A. -1.282
B. 1.645
C. -2.576
D. +2.576
The Intelligence Quotient (IQ) test scores for adults are normally distributed with a
mean of 100 and a standard deviation of 15. What is the probability we could select a
sample of 50 adults and find that the mean of this sample exceeds 104?
A. 0.0294
B. 0.9412
C. Approximately one
D. 0.9706
Which statistic is used to test hypotheses about individual regression coefficients?
A. t-statistic
B. z-statistic
C. Χ2(chi-square statistic)
D. F
A group of 100 students were surveyed about their interest in a new Economics major.
Interest was measured in terms of high, medium, or low. In the study, 30 students
responded high interest, 50 students responded medium interest, and 20 students
responded low interest. What is the best way to illustrate the relative frequency of
student interest?
A. Use a cumulative frequency polygon
B. Use a box plot
C. Use a pie chart
D. Use a frequency table
To calculate monthly typical seasonal indexes, after computing the ratio-to-moving
averages, the averages must be:
A. divided by 12.
B. multiplied by 12.
C. summed and divided by 12.
D. centered.
What does a typical market basket of goods and services include?
A. Bread
B. Beer
C. Milk
D. All of these
Which of the following statements is correct regarding the chi-square distribution?
A. The distribution is negatively skewed.
B. Chi-square is based on two sets of degrees of freedom, one for the numerator and
one for the denominator.
C. The shape of the distribution is based on the degrees of freedom.
D. The variance of the distribution is equal to one.
Data for selected fruits purchased at wholesale prices for 2005 and 2009 are shown
next.
What is the Paasche price index?
A. 112.70
B. 179.08
C. 111.97
D. 109.36
What is the test statistic for the sign test if the sample size is large?
A. Chi-square
B. Standard normal z
C. Binomial
D. Wilcoxon signed-rank
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 critical value of chi-square with α = 0.05?
A. 11.070
B. 12.592
C. 13.388
D. 15.033
For quarterly seasonal indexes, the total of the adjusted quarterly indexes will equal
_____.
A. 4.0
B. 1.0
C. 100%
D. a variable
Refer to the following breakdown of responses to a survey of “How confident are you
that you saved enough to retire?”
What type of chart should be used to describe the frequency table?
A. A pie chart
B. A bar chart
C. A histogram
D. A frequency polygon
The index that combines the advantages of two popular weighted indices is called
____________________.
Cost-of-living adjustments are based on the _______________________.
A multiple regression analysis showed the following ANOVA table result.
Based on the information in the ANOVA, what is the decision regarding the global null
hypothesis?
For a distribution of sample means with a known population standard deviation, about
_____ percent of the sample means are within one standard error of population mean.
A major credit card company has determined that customers charge between $100 and
$1100 per month. If the monthly amount charged is uniformly distributed, the standard
deviation of the monthly amount charged would be ________.
The Sea Mist Hotel collects customer satisfaction data daily. Yesterday, the hotel was
99% occupied and the manager wanted to quickly assess customer satisfaction. She
randomly selected 10 scores. The maximum score is 100 points. The mean score is
82.1. The 10 scores were:
What is the variance?
For a distribution of sample means with a known population standard deviation, about
_____ percent of the sample means are within three standard errors of population mean.
The only time the variance equals the standard deviation is when _____________.
For hypotheses that compare two population means, when is a pooled variance used?