An issue that faces individuals investing for retirement is allocating assets among
different investment choices. Suppose a study conducted 10 years ago showed that 65%
of investors preferred stocks to real estate as an investment. In a recent random sample
of 900 investors, 540 preferred real estate to stocks. Is this new data sufficient to allow
you to conclude that the proportion of investors preferring stocks to real estate has
declined from 10 years ago? Conduct your analysis at the α = 0.02 level of significance.
A) Because z = -1.915 is not less than -2.055, do not reject H0. A higher proportion of
investors prefer stocks today than 10 years ago.
B) Because z = -1.915 is not less than -2.055, do not reject H0. A lower proportion of
investors prefer stocks today than 10 years ago.
C) Because z = -3.145 is less than -2.055, reject H0. A lower proportion of investors
prefer stocks today than 10 years ago.
D) Because z = -3.145 is less than -2.055, reject H0. A higher proportion of investors
prefer stocks today than 10 years ago.
Hubble Construction Company has submitted a bid on a state government project that is
to be funded by the federal government’s stimulus money in Arizona. The price of the
bid was predetermined in the bid specifications. The contract is to be awarded on the
basis of a blind drawing from those who have bid. Five other companies have also
submitted bids.
Suppose that there are two contracts to be awarded by a blind draw. What is the
probability of Hubble winning both contracts? Assume sampling with replacement.
A) 0.2778
B) 0.1667
C) 0.6944
D) 0.0278
A major issue facing many states is whether to legalize casino gambling. Suppose the
governor of one state believes that more than 55% of the state’s registered voters would
favor some form of legal casino gambling. However, before backing a proposal to allow
such gambling, the governor has instructed his aides to conduct a statistical test on the
issue. To do this, the aides have hired a consulting firm to survey a simple random
sample of 300 voters in the state. Of these 300 voters, 175 actually favored legalized
gambling.
State the appropriate null and alternative hypotheses.
A) H0 : p = 0.58 Ha: p ≠ 0.58
B) H0 : p ≤ 0.55 Ha: p > 0.55
C) H0 : p = 0.55 Ha: p ≠ 0.55
D) H0 : p ≤ 0.58 Ha : p > 0.58
Assuming that potholes occur randomly along roads, the number of potholes per mile of
road could best be described by the:
A) binomial distribution.
B) Poisson distribution.
C) hypergeometric distribution.
D) continuous distribution
Micron Technology has sales offices located in four cities: Dallas, Seattle, Boston, and
Los Angeles. An analysis of the company’s accounts receivables reveals the number of
overdue invoices by days, as shown here.
Assume the invoices are stored and managed from a central database.
What is the probability that a randomly selected invoice from the database is from the
Boston sales office?
A) 0.2702
B) 0.0231
C) 0.3461
D) 0.7765
Given a binomial distribution with n = 8 and p = 0.40, obtain the mean.
A) 2.8
B) 3.2
C) 3.6
D) 4.2
For the following hypothesis test:
With n = 64 and p = 0.42, state the calculated value of the test statistic
A) t = 0.4122
B) t = 1.7291
C) z = 0.3266
D) z = 1.2412
At a sawmill in Oregon, a process improvement team measured the diameters for a
sample of 1,500 logs. The following summary statistics were computed:
Given this information, which of the following statements is correct?
A) The distribution of log diameters is symmetric.
B) A log that is over 20 inches in diameter can be considered an outlier.
C) The distribution of log diameters is right-skewed.
D) The distribution is left-skewed.
Which of the following is true regarding the MSE and MAD in forecasting?
A) The MAD will tend to be a larger value than the MSE.
B) The MSE is much more useful than the MAD.
C) The square root of the MSE provides a value that will be similar to the MAD.
D) The MAD will be equal to the MSE.
Use the following regression results to answer the question below.
Which of the following is true?
A) The correlation between x and y must be approximately 0.8851.
B) The correlation between x and y must be approximately -0.8851.
C) The correlation between x and y must be approximately 0.7835.
D) The correlation between x and y must be approximately -0.7835.
The human resources department at a major high tech company recently conducted an
employee satisfaction survey of 100 of its 3,000 employees. Data were collected on
such variables as age, gender, marital status, current salary, level of overall satisfaction
on a scale from 1 to 5, number of years with the company, and job title. Which of the
variables would be considered to be qualitative data?
A) Gender, marital status, job satisfaction, and job title
B) Age
C) Years with the company
D) All variables listed are qualitative.
When customers return a product to a store and the store asks the customer to indicate
the reason that the merchandise was returned, the resulting data are quantitative since
multiple people will be providing the data.
A recent study in the restaurant business determined that the mean tips for male waiters
per hour of work are $6.78 with a standard deviation of $2.11. The mean tips per hour
for female waiters are $7.86 with a standard deviation of $2.20. Based on this
information, which of the following statements do we know to be true?
A) The distribution of tips for both males and females is right-skewed.
B) The variation in tips received by females is more variable than males.
C) The median tips for females exceeds that of males.
D) On a relative basis, males have more variation in tips per hour than do females.
Respond to the following questions using this partially completed one-way ANOVA
table:
Fill in the ANOVA table with the missing values.
A) Between Samples df = 6, MSB = 290.833, F-ratio = 14.667, SSW = 4,759, MSW =
19.829
B) Between Samples df = 6, MSB = 290.833, F-ratio = 7.948, SSW = 4,759, MSW =
19.829
C) Between Samples df = 5, MSB = 290.833, F-ratio = 14.667, SSW = 4,759, MSW =
19.829
D) Between Samples df = 5, MSB = 290.833, F-ratio = 7.948, SSW = 4,759, MSW =
19.829
If the hypothesis test you are conducting is a two-tailed test, which of the following is a
possible step that you could take to increase the power of the test?
A) Reduce the sample size
B) Increase alpha
C) Increase beta
D) Use the t-distribution
Which of the following is not considered desirable when constructing a frequency
distribution for continuous data?
A) Open-ended classes
B) Mutually exclusive classes
C) Equal-width classes
D) All-inclusive classes