A study of 200 computer service firms revealed these incomes after taxes:
What is the probability that a particular firm selected has $1 million or more in income
after taxes?
A. 0.00
B. 0.25
C. 0.49
D. 0.51
What is the most optimistic of all possible maximin, maximax, and minimax regret
strategies?
A. Minimax
B. Maximax
C. Maximin
D. Minimax regret
A cola-dispensing machine is set to dispense a mean of 2.02 liters into a container
labeled 2 liters. Actual quantities dispensed vary and the amounts are normally
distributed with a standard deviation of 0.015 liters. What is the probability a container
will have less than 2 liters?
A. 0.0918
B. 0.3413
C. 0.1926
D. 0.8741
The total area of a normal probability distribution is _______.
A. Between -3.0 and 3.0
B. 1.00
C. Dependent on a value of “z”
D. Approximated by the binomial distribution
In multiple regression analysis, testing the global null hypothesis that all regression
coefficients are zero is based on __________.
A. A z-statistic
B. A t-statistic
C. An F-statistic
D. A binomial distribution
The final rankings of the top 20 NCAA college basketball teams are an example of
which level of measurement?
A. Nominal
B. Ordinal
C. Interval
D. Ratio
Consider the multiple regression model shown next between the dependent variable Y
and three independent variables X1, X2, and X3, which result in the following function:
For this model, there were 35 observations; SSR = 1400 and SSE = 600.
The critical F value at the 1% level of significance is _______.
A. 3.83
B. 2.61
C. 4.02
D. 2.53
As the size of the sample increases, what happens to the shape of the distribution of
sample means?
A. It cannot be predicted in advance.
B. It approaches a normal distribution.
C. It is positively skewed.
A hypothesis test that rho is zero is conducted at the 5% level of significance. If
Spearman’s (rho) is 0.86 for a sample of 15 observations, what is the computed value of
the t statistic?
A. 0.456
B. 6.08
C. 0.425
D. 2.16
Which shape describes a Poisson distribution?
A. Positively skewed
B. Negatively skewed
C. Symmetrical
D. All apply
A new machine is set or calibrated to fill tubes of toothpaste at precisely 6.75 ounces.
Then, once the machine is running, a sample of six tubes is taken every three hours and
weighed with the following results:
What is the value of A2, the control limit factor for averages?
A. 0
B. 1
C. 0.577
D. 0.483
What kind of distribution is the t distribution?
A. Continuous
B. Discrete
C. Subjective
D. A z distribution
For a given set of 12 ranked data values, the sum of the squared differences is 18. What
is Spearman’s coefficient of rank correlation for the data?
A. +0.7791
B. -0.7791
C. +0.2209
D. -0.2209
The average score of 100 students taking a statistics final was 70, with a standard
deviation of 7. Assuming a normal distribution, what is the probability that a student
scored 90 or higher?
A. 0.4979
B. 0.0021
C. 0.9979
D. 2.86
When testing the safety of cars using crash tests, a sample of one or two cars is used
because ___________.
A. sampling is more accurate
B. cars are destroyed
C. it is quicker
D. the population is very large
For the following distribution:
What is the mean of the distribution?
A. 2.1
B. 1.5
C. 0.441
D. 2
Contingency table analysis can be used to test for a relationship between two
_________ scale variables.
Over the last ten days, a manufacturer of cell phones counts the number of defective
phones created in each eight-hour shift. The results are shown next.
To construct a process control chart for the mean number defective, what is the upper
control limit?
The potential loss for an uncertain state of nature is called a ________________.
For an inverse relationship between two variables, the sign of the correlation coefficient
is __________________.
A nonparametric test is also called a __________ test.
A financial planner wants to compare the yield of income and growth mutual funds.
Fifty thousand dollars is invested in each of a sample of 35 income and 40 growth
funds. The mean increase for a two-year period for the income funds is $900. For the
growth funds, the mean increase is $875. Income funds have a sample standard
deviation of $35; growth funds have a sample standard deviation of $45. Assume that
the population standard deviations are equal. At the 0.05 significance level, is there a
difference in the mean yields of the two funds?
What is the p-value for the computed test statistic?
If the number of observations is 124, calculate the suggested number of classes using
the “2 to the k rule.”
When are two outcomes independent? Explain in terms of the rules of probability.
A new printing machine is set or calibrated to print 25 copies per minute. On each of
four days, the printer’s output is measured five times. The data will be used to construct
a process control chart to monitor the printing process. The results of the printing
process are in the following table.
What is the upper control limit (UCL) for the mean chart?