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Consider the following data.
Use Excel's Regression Tool to estimate a general linear model that uses a reciprocal
transformation on the dependent variable.
Exhibit 18-4
It has been hypothesized that there is no difference in the mathematical accuracy of men
and women. A sample of men and women were given math tests. The scores on the tests
are given below.
Refer to Exhibit 18-4. The null hypothesis is to be tested at the 5% level. The decision
rule is not to reject the null hypothesis if
a. -1.96 < z < 1.96
b. -1.645 < z < 1.645
c. z > 1.96 or z < -1.96
d. the number of "+" signs is greater than or equal to 2 but less than or equal to eight
In order to estimate the difference between the average Miles per Gallon of two
different models of automobiles, samples are taken and the following information is
collected.
One measure of the accuracy of a forecasting model is the
a. smoothing constant
b. trend pattern
c. mean absolute error
d. seasonal index
For the following data
Compute the following measures:
a. The mean
b. The variance
c. The standard deviation
d. The coefficient of variation
e. The 25th percentile
f. The median
g. The 75th percentile
Exhibit 20-4
Below you are given a payoff table involving two states of nature and three decision
alternatives.
The probability of occurrence of S1 = 0.3.
Refer to Exhibit 20-4. The recommended decision alternative based on the expected
value is
a. A
b. B
c. C
d. All alternatives are the same.
The difference between the expected value of an optimal strategy based on sample
information and the "best" expected value without any sample information is called the
a. optimal information
b. expected value of sample information
c. expected value of perfect information
d. efficiency of information
47. Exhibit 17-3
Consider the following time series.
Refer to Exhibit 17-3. The forecast for period 10 is
a. 6.7
b. -6.7
c. 23.3
d. 15
Exhibit 21-1
A simple random sample of size 64 is taken from a population of size 800. The sample
mean is determined to be 2,550 with a standard deviation of 500.
Refer to Exhibit 21-1. An estimate of the standard error of the mean (for the total) is
a. 62,500.50
b. 47,958.32
c. 7.8125
d. 50,000.00
A component of the time series model that results in the multi-period above-trend and
below-trend behavior of a time series is
a. a trend component
b. a cyclical component
c. a seasonal component
d. an irregular component
Exhibit 12-4
In the past, 35% of the students at ABC University were in the Business College, 35%
of the students were in the Liberal Arts College, and 30% of the students were in the
Education College. To see whether or not the proportions have changed, a sample of
300 students was taken. Ninety of the sample students are in the Business College, 120
are in the Liberal Arts College, and 90 are in the Education College.
Refer to Exhibit 12-4. This problem is an example of a
a. normally distributed variable
b. test for independence
c. Poisson distributed variable
d. multinomial population
A bank has kept records of the checking balances of its customers and determined that
the average daily balance of its customers is $300 with a standard deviation of $48. A
random sample of 144 checking accounts is selected.
a. What is the probability that the sample mean will be more than $306.60?
b. What is the probability that the sample mean will be less than $308?
c. What is the probability that the sample mean will be between $302 and $308?
d. What is the probability that the sample mean will be at least $296?
Exhibit 10-8
In order to determine whether or not there is a significant difference between the hourly
wages of two companies, the following data have been accumulated.
Refer to Exhibit 10-8. The p-value is
a. 0.0013
b. 0.0026
c. 0.0042
d. 0.0084
Part of an ANOVA table involving 8 groups for a study is shown below.
Of the last 100 customers entering a computer shop, 25 have purchased a computer. If
the classical method for computing probability is used, the probability that the next
customer will purchase a computer is
a. 0.25
b. 0.50
c. 1.00
d. 0.75
Exhibit 6-4
The starting salaries of individuals with an MBA degree are normally distributed with a
mean of $40,000 and a standard deviation of $5,000.
Refer to Exhibit 6-4. What percentage of MBA's will have starting salaries of $34,000
to $46,000?
a. 38.49%
b. 38.59%
c. 50%
d. 76.98%
Exhibit 15-5
Below you are given a partial Excel output based on a sample of 25 observations.
Refer to Exhibit 15-5. Carry out the test of significance for the parameter 1 at the 5%
level. The null hypothesis should be
a. rejected
b. not rejected
c. revised
d. None of these alternatives is correct.
Exhibit 8-2
The manager of a grocery store has taken a random sample of 100 customers. The
average length of time it took these 100 customers to check out was 3.0 minutes. It is
known that the standard deviation of the checkout time is one minute.
Refer to Exhibit 8-2. With a .95 probability, the sample mean will provide a margin of
error of
a. 0.95
b. 0.10
c. .196
d. 1.96
The sum of frequencies for all classes will always equal
a. 1
b. the number of elements in a data set
c. the number of classes
d. a value between 0 and 1
The standardized residual is provided by dividing each residual by
a. its mean residual
b. its corresponding x value
c. its standard deviation
d. its z-score
If the standard deviation for the lifetimes of washing machines is estimated to be 800
hours, how large a sample must be taken in order to be 97% confident that the margin
of error will not exceed 50 hours?
For the following observations, plot a scatter diagram and indicate what kind of
relationship (if any) exists between the amount of sugar in one serving of cereal (grams)
and the amount of fiber in one serving of cereal (grams).
A medical journal reported the following frequencies of deaths due to cardiac arrest for
each day of the week:
At a 5% level of significance, determine whether the number of deaths is uniform over
the week.
The following data represent the filling weights based on samples of 350-gram
containers. Ten samples of size 5 were taken. Use Excel to develop an R chart.
If the standard deviation of the lifetimes of vacuum cleaners is estimated to be 300
hours, how large of a sample must be taken in order to be 97% confident that the
margin of error will not exceed 40 hours?
To calculate an exponential smoothing forecast of demand, what values are required?
1. alpha, number of periods, last actual demand
2. alpha, last forecast, number of periods
3. alpha, last forecast, last actual demand
4. last forecast, number of periods, averaging period
5.
The sales records of a major auto manufacturer over the past ten years are shown below.
Develop a linear trend expression and project the sales (the number of cars sold) for
time period t = 11
