The standard error of the sample mean is equal to 5 when n=25.

The standard error of the sample mean is equal to 5 when n=25. If the sample size increases by a factor of four, how will the standard error change?

 A.   It will be cut to ¼ of 5 

 B.   It will quadruple 

 C.   It will be cut in half 

 D.   It will double 

Solution

The use of the student’s t distribution requires which of the following assumptions?

The use of the student’s t distribution requires which of the following assumptions?

 A.   The population is normal 

 B.   The sample is drawn from a positively skewed distribution 

 C.   The population variance is known 

 D.   The sample size is greater than 30 

Solution

The expected value of the sampling distribution of the sample mean

The expected value of the sampling distribution of the sample mean equals the population mean

 A.   when the population size N > 30. 

 B.   for all populations. 

 C.   when the population is symmetric. 

 D.   when the population is normally distributed. 

Solution

A random sample of 25 observations is selected from a normally distributed population.

A random sample of 25 observations is selected from a normally distributed population. The sample variance is 10. In the 95% confidence interval for the population variance, the upper limit will be 

 A.  17.331 

 B.  19.353 

 C.  6.097 

 D.  17.110 

Solution

A study of 200 insomniacs paid for by the Serta Mattress Company

A study of 200 insomniacs paid for by the Serta Mattress Company found that the average insomniac counted 350 sheep before falling asleep, with a standard deviation of 120. An insomniac is a person who has difficulty falling asleep. Some useful numbers might be:

=NORMSINV(0.89) 1.2265 

=NORMSINV(0.945) 1.5982 

=TINV(0.89,199) 0.1385 

=TINV(0.11,199) 1.6053 

=TINV(0.055,199) 1.9302 

Solution

Calculate an 89% confidence interval for the true mean number of sheep counted by insomniacs

Calculate an 89% confidence interval for the true mean number of sheep counted by insomniacs

 A.  350±13.62 

 B.  350±13.56 

 C.  350±16.38 

 D.  350±10.41 

 

Solution

To tell if the standard deviation of a process has changed, the control charts used are

 To tell if the standard deviation of a process has changed, the control charts used are

 A.  R and S charts. 

 B.  p and R charts. 

 C.  S and x bar charts. 

 D.   x bar and p charts

Solution

In statistical process control, a Type I error occurs if we decide that the process is

In statistical process control, a Type I error occurs if we decide that the process is

 A.   under control when it is under control. 

 B.   out of control when it is under control. 

 C.   out of control when it is out of control. 

 D.   under control when it is out of control. 

Solution

When the only sources of variation in a production process are caused by chance,

When the only sources of variation in a production process are caused by chance, the process is said to be

 A.   under control. 

 B.   out of control but in balance. 

 C.   out of control. 

 D.   out of balance but under control.

Solution

What is the difference between probability sampling and simple random sampling?

What is the difference between probability sampling and simple random sampling? 

A. Probability sampling is a type of simple random sample. 

B. In probability sampling each item has an identical chance of being chosen. 

C. There is no difference. 

D. Simple random sampling is a type of probability sampling. 

 

Solution

A sufficiently large coverage error will result in which of the following?

A sufficiently large coverage error will result in which of the following? 

A. Probability sampling 

B. Inability to perform inferential statistics 

C. Non-response bias 

D. Statistics about the actual population rather than the target population 

 

Solution

Which of the following statements is false?

Which of the following statements is false? 

A. Statistical inference is the process of making a prediction based on only a small piece of information. 

B. A summary measure calculated from all items of interest is a parameter. 

C. The main goal of descriptive statistics is to estimate characteristics of populations. 

D. A summary measure calculated from some of the items of interest is a statistic. 

Solution

Which of the following statements is NOT true?

 Which of the following statements is NOT true? 

A. A statistical test may be significant yet have no practical importance. 

B. Scientific progress consists of continual refinement of theories through hypothesis testing. 

C. Estimating parameters is an important aspect of descriptive statistics. 

D. Statistics is the science of collecting, organizing, analyzing, interpreting, and presenting data. 

 

Solution

Which of the following is an example of statistical inference?

Which of the following is an example of statistical inference? 

A. Calculating the amount of fly spray needed for your orchard next season. 

B. Counting the number of patients who file malpractice suits after being discharged from hospitals in New York State. 

C. Calculating the mean age of patients discharged from hospitals in New York State in 1997. 

D. Calculating the mean number of fruit trees damaged by Mediterranean fruit flies in California last year. 

 

Solution

Which of the following is an example of statistical inference?

Which of the following is an example of statistical inference? 

A. Calculating the amount of fly spray needed for your orchard next season. 

B. Counting the number of patients who file malpractice suits after being discharged from hospitals in New York State. 

C. Calculating the mean age of patients discharged from hospitals in New York State in 1997. 

D. Calculating the mean number of fruit trees damaged by Mediterranean fruit flies in California last year. 

 

Solution

If terms such as positive, negative, more than, and less than, are used,

If terms such as positive, negative, more than, and less than, are used, then these hypotheses are_________. 

A. nondirectional hypotheses 

B. directional hypotheses 

C. null hypotheses 

D. alternative hypotheses 

 

Solution

The manipulation of the independent variable is known as the ________.

The manipulation of the independent variable is known as the ________. 

A. experimental test 

B. treatment 

C. randomization 

D. validity 

 

Solution

Which of the following is NOT a potential source of survey error?

Which of the following is NOT a potential source of survey error? 

A. Interviewer error 

B. Standard error 

C. Measurement error 

D. Coverage error 

 Solution

Which of these is NOT an acceptable type of survey question?

Which of these is NOT an acceptable type of survey question? 

A. pictograms 

B. Likert scale 

C. ranking questions 

D. leading question 

 

Solution

Which of the following is NOT an ethical concern for the statistical researcher?

Which of the following is NOT an ethical concern for the statistical researcher? 

A. Informed consent 

B. Protection of confidentiality 

C. Use of sound methodology 

D. Monetary compensation 

 

Solution

Which of the following is not an ethical concern for the statistical researcher?

 Which of the following is not an ethical concern for the statistical researcher? 

A. Manipulation of data 

B. Privacy of privacy 

C. Inhumane treatment of animals 

D. Cite sources 

Solution

Which of the following is NOT an ethical concern for the statistical researcher?

 Which of the following is NOT an ethical concern for the statistical researcher? 

A. Accurate reporting of procedures 

B. Accepted procedures are followed 

C. Maintain data accuracy 

D. Conceal financial support 

Solution

A study of the scores on an in plant course in management principles

A study of the scores on an in plant course in management principles and the years of service of the employees enrolled in the course yielded the following statistics: Test Scores: mean=100 variance = 225 Years of Service: mean=5 variance = 81 Of test scores and years of service, which measure has the greater dispersion? 

A. The short-run effects of those changes are always more beneficial to society than are the long-run effects. 

B. Test scores 

C. Years of service 

D. It is impossible to tell. 

 

Solution

Textbook Price Number of Textbooks $25 to $35 2 35 to 45 16 45

Textbook Price Number of Textbooks $25 to $35 2 35 to 45 16 45 to 55 5 55 to 65 7 65 to 75 20 Estimate the standard deviation of the price of a textbook. 

A. 196.78 

B. 14.03 

C. 33.85 

D. 729.00 

 

Solution

Textbook Price Number of Textbooks $25 to $35 2 35 to 45 16 45

Textbook Price Number of Textbooks $25 to $35 2 35 to 45 16 45 to 55 5 55 to 65 7 65 to 75 20 Estimate the mean price of a textbook. 

A. $60.00 

B. $554.00 

C. $11.08 

D. $55.40 

 

Solution

Which measurement uses absolute values?

Which measurement uses absolute values? 

A. ratio correct 

B. ordinal scale 

C. interval scale 

D. harmonic scale 

 

Solution

Identify the scale which has no meaningful zero.

Identify the scale which has no meaningful zero. 

A. nominal 

B. ordinal 

C. ratio 

D. interval 

Solution

Which of these measurement scales has a rank order associated with its use?

Which of these measurement scales has a rank order associated with its use? 

A. Ratio 

B. Ordinal 

C. Likert 

D. Nominal 

 

Solution

Which of the following cannot generate a Poisson distribution?

Which of the following cannot generate a Poisson distribution? 

A. The number of people at a movie theatre on Friday evening 

B. The number of customers arriving at an ATM in a minute 

C. The number of goals in the World Cup soccer game 

D. The number of defects in a new automobile 

Solution

The local police department must write, on average,

The local police department must write, on average, 5 tickets a day to keep department revenues at budgeted levels. Suppose the number of tickets written per day follows a Poisson distribution with a mean of 5.5 tickets per day. Interpret the value of the mean. 

A. The number of tickets written most often is 5.5 tickets per day 

B. Half of the days have less than 5.5 tickets written and half of the days have more than 5.5 tickets written 

C. The mean cannot be interpreted. 

D. If we sampled all days, the arithmetic average or expected number of tickets written would be 5.5 tickets per day. 

 

Solution

The Big Red Arcade and Pizza Palace caters to young teens and sells

The Big Red Arcade and Pizza Palace caters to young teens and sells tokens to play arcade games for 25¢ each and slices of pizza for 50¢ each. The distribution of sales of pizza slices per customer and sales of arcade tokens per customer is below. # Slices of Pizza 0 1 2 3 4 5 Probability 0.05 0.10 0.20 0.30 0.15 0.20 # Arcade Games 0 1 2 3 4 5 Probability 0.01 0.04 0.15 0.20 0.25 0.35 What is the probability that revenues from pizza slice sales will be greater than $1.00 per customer? 

A. .95 

B. .65 

C. .43 

D. .85 

 

Solution

Which of these parameters associated with a binomial experiment will

Which of these parameters associated with a binomial experiment will produce a probability distribution with the smallest standard deviation; given n is the same for each situation? 

A. p = 0.3 

B. p = 0.5 

C. (1- p) = 0.1. 

D. p = 0.4

Solution

The average qualifying speed for a championship NASCAR race is 145.65

The average qualifying speed for a championship NASCAR race is 145.65 mph and the standard deviation is 9.45 mph. Only drivers who obtain z-scores greater than 1.2 will qualify for the race. If the speeds are normally distributed, what minimum speed must be clocked to compete for the trophy? 

A. 157.0 mph 

B. 146.9 mph 

C. 174.8 mph 

D. 155.2 mph

Solution

The use of the student’s t distribution requires which of the following assumptions?

 The use of the student’s t distribution requires which of the following assumptions? 

A. The population is normal 

B. The sample size is greater than 30 

C. The sample is drawn from a positively skewed distribution 

D. The population variance is known 

 

 Solution

The expected value of the sampling distribution of the sample mean equals

The expected value of the sampling distribution of the sample mean equals the population mean 

A. when the population size N > 30. 

B. when the population is normally distributed. 

C. for all populations. 

D. when the population is symmetric. 

 

Solution

A study of 200 insomniacs paid for by the Serta Mattress Company

A study of 200 insomniacs paid for by the Serta Mattress Company found that the average insomniac counted 350 sheep before falling asleep, with a standard deviation of 120. An insomniac is a person who has difficulty falling asleep. Some useful numbers might be: =NORMSINV(0.89) 1.2265 =NORMSINV(0.945) 1.5982 =TINV(0.89,199) 0.1385 =TINV(0.11,199) 1.6053 =TINV(0.055,199) 1.9302 Out of the 200 insomniacs, 98 reported regularly watching The Late Show with David Letterman before they began to count sheep.Calculate the margin of error for a 78% confidence interval of the true proportion of insomniacs who regularly watch David Letterman before counting sheep. 

A. 0.136 

B. 0.043 

C. 0.164 

D. 0.056 

Solution

A random sample of 25 observations is selected from a normally distributed population.

A random sample of 25 observations is selected from a normally distributed population. The sample variance is 10. In the 95% confidence interval for the population variance, the upper limit will be 

A. 17.331 

B. 17.110 

C. 19.353 

D. 6.097 

Solution

Summary statistics computed from two independent samples are as follows:

Summary statistics computed from two independent samples are as follows: n1 = 50, x1 = 175, s1 = 18.5, n2 = 42, x2 = 158, and s2 = 32.4. Construct a 95% confidence interval estimate for the difference between the means of two normally distributed populations, where the unknown population variances are assumed to not be equal. The upper confidence limit is 

A. 19.123. 

B. 28.212. 

C. 24.911. 

D. 5.788. 

Solution

When the only sources of variation in a production

When the only sources of variation in a production process are caused by chance, the process is said to be 

A. out of balance but under control. 

B. out of control but in balance. 

C. under control. 

D. out of control. 

 

Solution

When the results of a process are either defective or acceptable,

When the results of a process are either defective or acceptable, the charts used for SPC are called 

A. control charts for attributes. 

B. control charts for variables. 

C. control charts for in control process. 

D. control charts for out of control process. 

 

Solution

When no point lies outside the control limits of a chart,

When no point lies outside the control limits of a chart, we conclude that variation in the process is 

A. due to special causes and there is not enough evidence to infer that the process is out of control. 

B. due to special causes and there is enough evidence to infer that the process is under control. 

C. due to common cause and there is enough evidence to infer that the process is out of control. 

D. due to common cause and there is not eno

Solution

The statement that determines if the null hypothesis is rejected or not is called the

 The statement that determines if the null hypothesis is rejected or not is called the

A.   critical value

B.   alternate hypothesis 

C.   test statistic 

D.   decision rule

Solution

A hypothesis test that involves a small sample requires that we make

The area of rejection, on a bell shaped curve, defines the location of all those values that are 

A.   so small or so large that the probability of their occurrence under a true null hypothesis is rather slim 

B.   so small or so large that the probability of their occurrence under a true null hypothesis is to be expected

C.   within the selected confidence interval for the test

D.   so small or so large that the probability of their occurrence under a false null hypothesis is rather remote

Solution

K and S Construction, located in Phoenix, Arizona, is working on its

K & S Construction, located in Phoenix, Arizona, is working on its business plan for the upcoming year. They did a study to determine if they should focus on building condominiums or individual houses. A building study, which had been conducted by the state, indicated that 60 percent of those families looking to buy a home in Arizona desired to buy a condominium. K & S Construction wanted to know if this figure applied to Phoenix. They collected a sample of 500 individuals that had expressed plans to buy a new home. The z-distribution was selected for this proportion test. The null hypothesis is p = 0.60 and the alternate is p ≠ 0.60. The significant level selected was .05. From the sample of 500, it was determined that 290 wanted to buy a condominium. What decision should be made regarding the null hypothesis? 

A.   The test level of .05 is not acceptable 

B.   Cannot accept nor reject it based on the information given 

C.   Fail to reject it

D.   Reject it 

Solution

A statistician was setting up a hypothesis test with

A statistician was setting up a hypothesis test with a level of significance dictated by upper management. However, she was concerned that the test she wished to perform might have unacceptable large possibilities of Type II error, ß. Which of the following would solve this problem? 

A.   Convince upper management to reduce the level of significance of the test. 

B.   Convince upper management to use a smaller p-value.

C.   Convince upper management to use a larger p-value.

D.   C

Solution

Doi Winery has two wine shops in the neighboring towns of Seamen and Batavia.

Doi Winery has two wine shops in the neighboring towns of Seamen and Batavia. The favorite wine, as advertised, is Raspberry wine. A survey of 300 customers at the Seamen store revealed that 225 individuals preferred the Raspberry wine while 290 out of 400 in Batavia preferred the same flavor. To test the hypothesis that there was no difference in preferences in the two towns, what is the alternate hypothesis? 

A.   µ1 ≠ µ2

B.   µ1 = µ2 

C.   µ1 < µ2

D.   µ1 > µ2 

Solution

A machine is set to fill the small size packages of Good and Better

 A machine is set to fill the small size packages of Good and Better candies are packaged with 60 pieces of candies in each bag. Sampling results revealed: 3 bags of 61, 2 bags of 59, 1 bag of 58, and 2 bags of 62. How many degrees of freedom are there? 

A.   7

B.   8

C.   9

D.    1 

Solution

Newton’s, a tire manufacturer, wanted to set a mileage guarantee on its new Road Warrior 60 tire.

Newton’s, a tire manufacturer, wanted to set a mileage guarantee on its new Road Warrior 60 tire. A sample test of 500 tires revealed that the tire’s mileage is normally distributed with a mean of 50,000 miles and a standard deviation of 1,750 miles. The warranty on the tires is presently set at 47,500 miles. The z-test statistic result was 1.43. The manufacturer wanted to determine if the tires were exceeding the guarantee. At the .05 significant level, it was concluded that the tires are exceeding the manufacturer’s guarantee. 

A.   The evidence does not support this decision.

B.   This was the correct decision.

C.   A decision cannot be made.

D.   The decision needs to be delay until more data is collected.

Solution

A recent study by College Stat Company reported a nationwide survey

A recent study by College Stat Company reported a nationwide survey of college students determined that students spend 2 hours studying for each hour in the classroom. Professor Baker at State College wants to determine whether the time students spend at her college is significantly different from the national average of 2 hours. A random sample of 20 statistics students resulted in an average of 1.75 hours with a standard deviation of 0.24 hours. A t-test was conducted at the 5% level of significance. The calculated value of t was -4.03. What was Professor Baker decision? 

A.   Reject the alternative hypothesis statement.

B.   Fail to reject the null hypothesis.

C.   Reject the null hypothesis, the test statistic exceeds the critical value.

D.   Cannot make a decision at this time; more data is required.

Solution

In which phase of new-product design process are considerations to target market,

In which phase of new-product design process are considerations to target market, desired level of performance, investment requirements and financial impact made:
A. preliminary process design
B. concept development and product planning
C. detailed engineering
D. pilot manufacturing phase

 

Solution

An example of prevention quality cost is:

An example of prevention quality cost is:
A. Train personnel
B. Inspection
C. Testing
D. Rework

 

Solution

esting is an example of:

Testing is an example of:
A. Internal failure costs
B. External failure costs
C. Prevention costs
D. Appraisal costs

 

Solution

Which of the following is not a dimension of design quality?

Which of the following is not a dimension of design quality?
A. Serviceability
B. Customization
C. Durability
D. Features

 

Solution

Which of the following is not a principle of work-center scheduling?

Which of the following is not a principle of work-center scheduling?
A. Schedule jobs as strings, with process steps back to back
B. Obtain feedback each day on the jobs that are completed at each work center
C. Reschedule every day
D. Once started, a job should not be interrupted

 

Solution

assignment method is appropriate in solving problems that have the following characteristics:

The assignment method is appropriate in solving problems that have the following characteristics:
A. There are ‘n’ things to be distributed to ‘n’ destinations
B. Though each destination may handle all the things, the final assignment has each thing assigned to one and only one destination
C. Only one criterion should be used (minimum cost, maximum profit, for example)
D. A and C

 

Solution

The objectives of work-center scheduling include(s):

The objectives of work-center scheduling include(s):
A. To meet due dates
B. To minimize lead times
C. To minimize finish goods inventory
D. A and B

 

Solution

According to Goldratt and Fox, a useful performance measure to treat inventory is ______.

According to Goldratt and Fox, a useful performance measure to treat inventory is ______.
A. Quick ratio
B. Dollar days
C. Current ratio
D. Inventory turnover

 

Solution

Which of the following according to Goldratt is not a component of production cycle time?

Which of the following according to Goldratt is not a component of production cycle time?
A. Wait time
B. Maintenance time
C. Process time
D. Setup time

 

Solution

The measures of the firm’s ability to make money according to Goldratt include:

The measures of the firm’s ability to make money according to Goldratt include:
A. Net profit
B. Return on assets
C. Cash flow
D. A and C

 

Solution

The advantage(s) of the network planning models over the Gantt chart is (are) that:

The advantage(s) of the network planning models over the Gantt chart is (are) that:
A. they are easy to use and quite widely understood
B. the precedence relationships in network scheduling are explicitly shown
C. they are less costly to use
D. both A and B

 

Solution

According to Hau Lee, which of the following types of products need to

According to Hau Lee, which of the following types of products need to be delivered with efficient supply-chains?
A. Grocery products
B. High technology products
C. Innovative products
D. Custom products

 

Solution

Supply-chain response relates to the following:

Supply-chain response relates to the following:
A. How quickly a customer order can be filled
B. How quickly a company can react to a new competing product
C. How inexpensive the product is
D. A and B

 

Solution

Which of the following product promotional activities would probably

Which of the following product promotional activities would probably help make the supply chain more efficient?
A. Special packaging for a specific event that occurs one time each year
B. A 2 for 1 price promotion
C. An “everyday” low price strategy where prices are not dependent on quantity delivered with a specific order
D. Price promotions that expire on a specific date

 

Solution

The steps to determining capacity requirements include:

The steps to determining capacity requirements include:
A. Using decision trees to evaluate capacity alternatives
B. Calculating equipment and labor requirements to meet product line forecasts
C. Projecting labor and equipment availabilities over the planning horizon
D. B and C

 

Solution

Which of the following statements is not true about capacity management in operations?

Which of the following statements is not true about capacity management in operations?
A. Capacity planning itself has different meaning to individuals at different levels within the operations management hierarchy.
B. The definition of capacity, in an operations management context, makes a clear distinction between efficient and inefficient use of capacity.
C. An operations management view also emphasizes the time dimension of capacity.
D. When looking at capacity, operations managers need to look at both resource input and product outputs.

 

Solution

A kanban card is used to signal that:

A kanban card is used to signal that:
A. a machine has broken down
B. work is authorized to replenish a downstream station
C. a worker has run out of parts
D. work is ready to be moved to the next station

 

Solution

Which of the following is not true about JIT systems?

Which of the following is not true about JIT systems?
A. JIT is typically applied to repetitive manufacturing.
B. The goal of JIT is to drive all inventory queues to a moderate level thus minimizing inventory investment and shortening lead times.
C. Under JIT the ideal lot size is one.
D. The JIT system is based on the philosophy of eliminating waste and utilizing the full capability of the worker.

 

Solution

Which of the following would not be classified as a time-series technique?

Which of the following would not be classified as a time-series technique?
A. Box Jenkins technique
B. Regression model
C. Exponential smoothing
D. Simple moving average

Solution

Given that the previous forecast of 65 turned out to be four units less than the actual demand.

Given that the previous forecast of 65 turned out to be four units less than the actual demand. The next forecast is 66. What would be the value of alpha if the simple exponential smoothing forecast method is being used?
A. 0.04
B. 0.25
C. 0.4
D. 0.02

 

Solution