For a population that is not normally distributed, the distribution of the sample means
will ________.
A. Be negatively skewed
B. Approach a normal distribution
C. Be positively skewed
D. Take the same shape as the population
The following graph is a:
A. Dot plot
B. Stem-and-leaf display
C. Box plot
D. Contingency table
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 75 or more successes using the normal
distribution to approximate the binomial. Applying the continuity correction factor,
what value would be used to calculate a z-score?
A. 74.5
B. 75
C. 75.5
D. 25
A confidence interval for a population mean __________.
A. estimates the population range
B. estimates a likely interval for a population mean
C. estimates likelihood or probability
D. estimates the population standard deviation
For the following distribution:
What is the mean of the distribution?
A. 1
B. 2.5
C. 1.604
D. 3
A sign test is a:
A. parametric method used to determine the differences between two related
observations.
B. nonparametric method based on the sign of a difference between two related
observations.
C. nonparametric method for that uses the Chi-square distributions as the test statistic.
D. parametric method for determining the differences between related observations
where distribution dependent tests are used.
To test the hypothesis, the Wilcoxon signed-rank test uses a:
A. z statistic.
B. t test statistic.
C. chi-square statistic.
D. Student’s t statistic.
The Office of Student Services at a large western state university maintains information
on the study habits of its full-time students. Their studies indicate that the mean amount
of time undergraduate students study per week is 20 hours. The hours studied follows
the normal distribution with a standard deviation of six hours. Suppose we select a
random sample of 144 current students. What is the probability that the mean of this
sample is between 19.25 hours and 21.0 hours?
A. 0.9544
B. 0.0160
C. 0.0986
D. 0.9104
What chart helps to identify the relatively few factors that impact the performance of a
manufacturing or service process?
A. SPC
B. Pareto analysis
C. Fishbone chart analysis
D. Diagnostic chart
David’s gasoline station offers 4 cents off per gallon if the customer pays in cash and
does not use a credit card. Past evidence indicates that 40% of all customers pay in
cash. During a one-hour period, 15 customers buy gasoline at this station. What is the
probability that more than 8 and less than 12 customers pay in cash?
A. 0.210
B. 0.212
C. 0.092
D. 0.562
The 67th percentile is:
A. the value above which 67 percent of the observations occur.
B. a value one less than 67 percent of the observations.
C. the value below which 67 percent of the observations occur.
D. the value of the observation at the 67th location.
The first card selected from a standard 52-card deck was a king. If it is NOT returned to
the deck, what is the probability that a king will be drawn on the second selection?
A. 1/3 or 0.33
B. 1/51 or 0.0196
C. 3/51 or 0.0588
D. 1/13 or 0.077
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 sum of the ranks for flavor #2?
A. 153
B. 139
C. 144
D. 156
To determine whether four population means are equal, a sample from each population
was selected at random. Using the Kruskal-Wallis test, H was computed to be 2.09.
What is our decision at the 0.05 level of risk?
A. Fail to reject the null hypothesis because 0.05 < 2.09.
B. Fail to reject the null hypothesis because 2.09 < 7.815.
C. Reject the null hypothesis because 7.815 > 2.09.
D. Reject the null hypothesis because 2.09 > critical value of 1.96.
To calculate monthly typical seasonal indexes, a specific seasonal index must be
computed for:
A. every month.
B. every year.
C. every quarter.
D. every day.
A linear trend equation is used to represent time series values when the data are
changing by equal what?
A. Percents
B. Proportions
C. Amounts
D. Both percents and proportions are correct.
Using the following information:
What is the standard error of the estimate?
A. 136.8552
B. 1094.842
C. 11.6985
D. 13418.4
A fishbone diagram is an ________________ tool.
The shape of the F distribution is _____________________.
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.
To test the hypothesis that the frequency distribution is normally distributed, what is the
value of the chi-square critical value at the .05 level of significance?
If a dependent variable and one of the independent variables are inversely related, the
sign for the regression coefficient of the independent variable is ____________.
When observing a checkout line at a food store, the average number of people served is
15 per hour. Using the Poisson distribution, what is the probability that 10 people check
out in any given hour?
Other things being equal, a smaller sample size would result in a wider confidence
interval because the standard error of the mean is ______________.