A commuter travels many miles to work each morning. She has timed this trip 5 times
during the last month. The time (in minutes) required to make this trip was 34, 39, 41,
35, and 41. The mean time (in minutes) required for this trip was _______.
a) 35
b) 41
c) 37.5
d) 38
e) 35.5
The mean life of a particular brand of light bulb is 1200 hours and the standard
deviation is 75 hours. Tests show that the life of the bulb is approximately normally
distributed. It can be concluded that approximately 68% of the bulbs will last between
_______.
a) 900 and 1100 hours
b) 950 and 1050 hours
c) 975 and 1475 hours
d) 1050 and 1350 hours
e) 1125 and 1275 hours
A company believes that it controls more than 30% of the total market share for one of
its products. To prove this belief, a random sample of 144 purchases of this product is
contacted. It is found that 50 of the 144 purchased this company’s brand of the product.
If a researcher wants to conduct a statistical test for this problem, the observed zvalue
would be _______.
a) 0.05
b) 0.103
c) 0.35
d) 1.24
e) 1.67
A multiple regression analysis produced the following tables.
Using
= 0.05 to test the null hypothesis H0:
1= 0, the correct decision is ____.
a) fail to reject the null hypothesis
b) reject the null hypothesis
c) fail to reject the alternative hypothesis
d) reject the alternative hypothesis
e) there is not enought information provided to make a decision
Suppose you are working with a data set that is normally distributed with a mean of 400
and a standard deviation of 20. Determine the value of xsuch that 60% of the values are
greater than x.
a) 404.5
b) 395.5
c) 405.0
d) 395.0
e) 415.0
Tamara Hill, fund manager of the Hill Value Fund, manages a portfolio of 250 common
stocks. Tamara is searching for a ‘low risk’ issue to add to the portfolio, i.e., one with a
price variance less than that of the S&P 500 index. Moreover, she assumes an issue is
not ‘low risk’ until demonstrated otherwise. Her staff reported that during the last nine
quarters the price variance for the S&P 500 index (population 1) was 25, and for the last
seven quarters the price variance for XYC common (population 2) was 8. Assume that
stock prices are normally distributed in the population. Using
= 0.05, the critical
Fvalue is _______.
a) 3.68
b) 3.58
c) 4.15
d) 3.29
e) 4.89
Data from a randomized block design are shown in the following table.
Using
= 0.05, the observed F value for the treatments null hypothesis is _____.
a) 5.14
b) 0.37
c) 1.17
d) 0.22
e) 2.00
The city golf course is interested in starting a junior golf program. The golf pro has
collected data on the number of youths under 13 that have played golf during the last 4
months. Using a three-month moving average (with weights of 5, 3, and 1 for the most
current value, next most current value and oldest value, respectively), the forecast value
for November in the following time series would be ____________.
a) 24
b) 21
c) 21.56
d) 19.22
e) 22
Suppose the total time to fill a routine prescription at a local pharmacy is 35 minutes
based on the time the physician places the order to the time it is dispensed. Assume the
standard deviation is 11 minutes.. A zscore was calculated for a number, and the zscore
is 3.4. What is x?
a) 37.4
b) 72.4
c) 0.00
d) 68.0
e) 2.0.8
Data from a randomized block design are shown in the following table.
With
= 0.05, the observed F value for the blocking effects null hypothesis is__.
a) 0.37
b) 5.14
c) 1.17
d) 2.33
e) 2.00
Consider the relative frequency distribution given below:
There were 60 numbers in the data set. How many numbers were in the interval
40-under 60?
a) 30
b) 50
c) 18
d) 12
e) 15
A researcher is interested in estimating the mean weight of a semi tracker truck to
determine the potential load capacity. She takes a random sample of 17 trucks and
computes a sample mean of 20,000 pounds with sample standard deviation of
1,500.The 95% confidence interval for the population mean weight of a semi tracker
truck is ______________.
a) 19,232 to 20,768b) 19,365 to 20,635c) 19,229 to 20,771
d) 19,367 to 20,633
e) 119.89 to 122.1218,500 to 21,500
The following ANOVA table is from a multiple regression analysis.
The adjusted R2value is __________.
a) 0.65
b) 0.39
c) 0.61
d) 0.53
e) 0.78
Velma Vasquez, fund manager of the Vasquez Value Fund, manages a portfolio of 250
common stocks. Velma relies on various statistics, such as variance, to assess the
overall risk of stocks in an economic sector. Her staff reported that for a sample 14
utility stocks the mean annualized return was 14% and that the variance was 3%.
Assume that annualized returns are normally distributed. The 95% confidence interval
for the population variance of annualized returns is _______.
a) 0.018 to 0.064
b) 0.016 to 0.078
c) 0.017 to 0.066
d) 0.016 to 0.075
e) 0.020 to 0.080
If x, the time (in minutes) to complete an change job at certain auto service station, is
uniformly distributed over the interval 20 to 30, inclusively (20 x 30), then the
probability that an oil change job is completed in 25 to 28 minutes, inclusively, i.e.,
P(25 x 28) is __________________.
a) 0.250
b) 0.500
c) 0.300
d) 0.750
e) 81.000
Which of the following quality control chart conditions is an indicator that the process
is potentially out-of-control?
a) several consecutive data points between the UCL and the LCL
b) a data point above the LCL
c) a data point above the UCL
d) a data point in the outer 1/3 region
e) a data point on the center line
In decision-making under uncertainty, a pessimistic approach is the __________.
a) maximin criterion
b) maximax criterion
c) Hurwicz criterion
d) minimax regret strategy
e) maximin regret strategy
For the following ANOVA table, the HSD value, assume equal sample sizes and using
= 0.01 is ______
a) 0.81
b) 0.55
c) 0.48
d) 0.43
e) 0.68
A researcher is testing a
hypothesis of a single
mean. The critical
zvalue for
= .05 and a two”tailed test is +1.96. The observed zvalue from sample data is 2.85. The
decision made by the researcher based on this information is to _____ the null
hypothesis.
a) reject
b) fail to reject
c) redefine
d) change the alternate hypothesis into
e) restate the null hypothesis
A time series analysis was performed to determine the number of new online customers
that joined the “Jelly of the Month Club”. The actual number of new customers, the
forecast values and error terms is presented in the following table. The mean squared
error (MSE) for this forecast is ___________.
a) -0.50
b) 0.50
c) 1.50
d) 7.00
e) 3.00
The list of all elementary events for an experiment is called _______.
a) the sample space
b) the exhaustive list
c) the population space
d) the event union
e) a frame
One hundred policyholders file claims with CareFree Insurance. Ten of these claims are
fraudulent. Claims manager Earl Evans randomly selects four of the one hundred claims
for thorough investigation. If x represents the number of fraudulent claims in Earl’s
sample, x has a _______________.
a) normal distribution
b) hypergeometric distribution, but may be approximated by a binomial
c) binomial distribution, but may be approximated by a normal
d) binomial distribution, but may be approximated by a Poisson
e) exponential distribution
The expected (mean) life of a particular type of light bulb is 1,000 hours with a standard
deviation of 50 hours. The life of this bulb is normally distributed. What is the
probability that a randomly selected bulb would last fewer than 940 hours?
a) 0.3849
b) 0.8849
c) 0.1151
d) 0.6151
e) 0.6563
Sarah Soliz, Director of Quality Programs, is designing and R charts for the
rod shearing process at Stockton Steel. She has 26 samples of rod length, and each
sample included measurements of 5 rods. The mean of the 26 sample means is 112
inches, and mean of the 26 ranges is 0.15 inch. The lower control limit for her R chart is
____.
a) 0.150
b) 0.000
c) 0.317
d) 2.114
e) 1.000
Given P (A) = 0.45, P (B) = 0.30, P (A B) = 0.05. Find P (B|A).
a) 0.45
b) 0.135
c) 0.30
d) 0.111
e) 0.167
Let zbe a normal random variable with mean 0 and standard deviation 1. What is P(z<
1.3)?
a) 0.4032
b) 0.9032
c) 0.0968
d) 0.3485
e) 0. 5485
Let xbe a binomial random variable withn=50 andp=.3. If we use the normal
distribution to approximate probabilities for this, a correction for continuity should be
made. To find the probability of more than 15 successes, we should find _______.
a) P(x>15.5)
b) P(x>15)
c) P(x>14.5)
d) P(x<14.5)
e) P(x< 15)
The executives of CareFree Insurance, Inc. feel that “a majority of our employees
perceive a participatory management style at CareFree.” A random sample of 200
CareFree employees is selected to test this hypothesis at the 0.05 level of significance.
Ninety employees rate the management as participatory. The appropriate decision is
__________.
a) fail to reject the null hypothesis
b) reject the null hypothesis
c) reduce the sample size
d) increase the sample size
e) maintain status quo
The following scatter plot indicates that _________.
a) a x2transform may be useful
b) a log y transform may be useful
c) a x4transform may be useful
d) no transform is needed
e) a x3transform may be useful
Using a three-month moving average (with weights of 6, 3, and 1 for the most current
value, next most current value and oldest value, respectively), the forecast value for
October made at the end of September in the following time series would
be__________.
a) 11.60
b) 10.00
c) 9.67
d) 8.60
e) 6.11