A survey item asked students to indicate their class in college: freshman, sophomore,
junior, or senior. Which measure(s) of central location would be appropriate for the data
generated by that questionnaire item?
A. Mean and median
B. Mean and mode
C. Mode and median
D. Mode only
Which of the following is a characteristic of the F distribution?
A. Normally distributed
B. Positively skewed
C. Negatively skewed
D. Equal to the t distribution
The forecast for the third quarter is 2,000 units; the seasonal index for the quarter is
1.18. What are the seasonally adjusted sales for the quarter?
A. 2,000
B. 2,018
C. 2,118
D. 2,360
In a frequency distribution, the number of observations in a class is called the class
________.
A. Midpoint
B. Interval
C. Array
D. Frequency
A recent study focused on the amount of money single men and women save monthly.
The information is summarized next. Assume that the population standard deviations
are equal.
At the .01 significance level, do women save more money than men? What is the
critical value for this hypothesis test?
A. +6.213
B. +2.369
C. +2.632
D. +2.40
The moving average method smoothes out the fluctuations in the data.
A survey of property owners’ opinions about a street-widening project was taken to
determine if owners’ opinions were related to the distance between their home and the
street. A randomly selected sample of 100 property owners was contacted and the
results are shown next.
What is the critical value at the 5% level of significance?
A. 7.779
B. 9.488
C. 9.236
D. 11.070
Given a linear time series trend Ŷ = 5.2 + 3.1t, what is the forecast for 2010 if the time
series started in 2003?
A. 23.8
B. 26.9
C. 30.0
D. 21.7
In acceptance sampling, the risk of accepting a poor quality lot is known as:
A. consumer’s risk.
B. producer’s risk.
C. a Type I error.
D. None of these alternatives is correct.
What process investigates the potential causes of an outcome or effect such as poor
quality?
A. SPC
B. Pareto analysis
C. Fishbone chart analysis
D. Diagnostic chart
Data for selected vegetables purchased at wholesale prices for 1995 and 2007 are
shown next.
What is Fisher’s ideal index?
A. 107.5
B. 102.7
C. 112.8
D. 103.2
Which measures of central location are not affected by extremely small or extremely
large values?
A. Mean and median
B. Mean and mode
C. Mode and median
D. Standard deviation and mean
Assume the least squares equation is Ŷ = 10 + 20X. What does the value of 10 in the
equation indicate?
A. When X = 0, Y = 10.
B. X increases by 10 for each unit increase in Y.
C. Y increases by 10 for each unit increase in X.
D. It is the error of estimation.
An investigation of the effectiveness of a training program to improve customer
relationships included a pre-training and post-training customer survey. To compare the
differences they computed (post-training survey score – pre-training survey score).
Seven customers were randomly selected and completed both surveys. The results
follow.
For a 0.05 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 training was effective.
B. Reject the null hypothesis and conclude that the training was ineffective.
C. Fail to reject the null hypothesis and conclude that the mean survey scores are the
same.
D. Fail to reject the null hypothesis and conclude that the mean survey scores are not
equal.
As chief statistician for the county, you want to compute and publish every year a
special-purpose index, which you plan to call Index of County Business Activity. Three
series seem to hold promise as the basis for the index; namely, the price of cotton, the
number of new cars sold, and the rate of money turnover for the county (published by a
local bank). Arbitrarily you decide that money turnover should have a weight of 60
percent; number of new cars sold, 30 percent; and the price of cotton, 10 percent.
What is the Index of County Business Activity for 1981 (the base year) and for 2006?
A. 100 for 1981, 139 for 2006
B. 139 for 1981, 100 for 2006
C. 100 for 1981, 61 for 2006
D. 100 for 1981, 100 for 2006
What is the area under the normal curve between z = 0.0 and z = 1.79?
A. 0.4633
B. 0.0367
C. 0.9599
D. 0.0401
A recent study focused on the amount of money single men and women save monthly.
The information is summarized next. Assume that the population standard deviations
are equal.
At the .01 significance level, what is the conclusion about the way women and men
save?
A. Reject the null hypothesis and conclude that women save more than men.
B. Reject the null hypothesis and conclude that women and men save the same amount.
C. Fail to reject the null hypothesis.
D. Fail to reject the null hypothesis and conclude the means are different.
An airline is investigating the causes of lost bags. The following table of data was
collected over the last six months.
What is the reason with the lowest percentage of bags is lost, and what is the
percentage?
Data for selected fruits purchased at wholesale prices for 2005 and 2009 are shown
next.
What is the simple price relative for navel oranges?
The statistical technique used to test the equality of three or more population means is
___________________.
For the following data, what relationship is shown in the graph?
A tire manufacturing company is reviewing its warranty for their rainmaker tire. The
warranty is for 40,000 miles. The distribution of tire wear is normally distributed with a
population standard deviation of 15,000 miles. The tire company believes that the tire
actually lasts more than 40,000 miles. A sample of 49 tires revealed that the mean
number of miles is 45,000 miles. To test the hypothesis at a 0.05 significance level,
what is the computed test statistic?
If the null hypothesis, H0: β1 = 0, is rejected, the independent variable, X1, it has a
______ effect on the dependent variable.
ANOVA requires that the populations should be ______, ______, and have _____.