Six Sigma Green Belt Test Prep
Over 200,000 customer transactions are processed. Two hundred defects are reported. What is the DPMO.
1000
An S-Chart is used for continuous data and whenever the sample size is greater than:
12
A process has a mean of 20 and a standard deviation of 1. It is normally distributed. Approximately 5 percent (ignore rounding) of the observations would fall outside _______________.
18 to 22
The following is a regression equation. Y= 10 + 35 X. If X is 5 the value of Y is ____________
225
Which of the following represents the number of Defects Per Million Outcomes associated when a process has been designed to meet Six-Sigma standards.
3.4
The following sample data tells us how long it took for a manufacturer of cell phones to repair five defective phones still on warranty. The range for this data is __________ days. 22, 34, 17, 16, 27
34 to 16
A company using Six Sigma is operating at a 99.99967 defect-free rate. What is the Sigma Level and DPMO.
6 sigma, 3.4 DPMO
Which statistical tool is used to gain insight into the extent of a relationship between two or more variables.
ANOVA
Establishing a ____________ is necessary when creating a process control chart.
All of the above
Which of the following terms represents the characteristics or specifications of the product or service necessary to meet the needs and wants of the customer.
Critical to Quality, CTQ
The acronym VOC refers to the voice of the ____________ .
Customer
DPMO is an acronym for which of the following?
Defects Per Million Opportunities
Drawing a process flow diagram is usually associated with the ____________ phase of the lean-six sigma process.
Define
The distribution that describes the way in which sample means of a certain size are distributed about the population mean is called the ___
Distribution of Sample Means
Lean focuses on ___while Six-Sigma focuses on ____
Efficiency, consistency
Which of the following is one of the challenges addressed by Lean
Establishing standrds for quality control
Which of the following tools is used to anticipate how a process, product or service might fail to meet output expectations
Failure Mode and Effects Analysis
A Fishbone diagram breaks a problem down into possible sources that have contributed to the problem.
False
If designed properly, no more than a single histogram would be needed to find the root cause of a problem.
False
In most processes it is possible to eliminate all variation as long as the process has been designed using best practices.
False
Minimizing waste is not one of the objectives of a Six Sigma Analysis
False
Raising the LCL and lowering the UCL, in the absence of any other changes, will have no effect on the process mean.
False
Special Cause variation is always present to some degree in any process.
False
The means of small samples taken from a population are more likely to be closer to population mean that are the means of much larger samples taken from that same population.
False
The process mean and process target are never the same.
False
When R-squared in a multiple regression analysis is 0.72 this suggests that 72 percent of the variation in the dependent variable can be explained by variation in the independent variables.
False
An Ishikawa Diagram is also known as a _________________
Fishbone diagram
Which of the following is not part of the DMAIC cycle?
Install
Which of the following is not determined by using the short cut formulas for process control charts
LSL
Which of the following express a customers quality expectations?
Lower specification limits and upper specifications limits
when the assumption of normality cannot be assured, which of the following hypothesis tests can be used to test the difference between tow means
Mann Whitney
One of the objectives in Lean is to minimize or eliminate
Non-value added activities
An insurance company monitors customer complaints. There are several possible problem categories including wrong bill sent, charges too high, failure to add new coverage, deletion of existing coverage and incorrect address. Which of the following can be used to determine the percentage that each problem contributes to customer complaints.
Pareto Diagram
A Value Stream Map is used primarily to improve ____________
Process Efficiency
The ability of a process to meet customer service levels is called ___________.
Quality Effectiveness Rating
Which of the following is used to identify and display inputs, suppliers, outputs, process and customers
SIPOC
Consistency of output is primarily associated with ________________ .
Six Sigma
Which of the following is not considered a hypothesis test?
Standard Error of the Mean Test
An x-bar chart for larger sample sizex, N>25 uses the ___ to determine the UCL and LCL
Standard error of the mean
An online retailer monitors customer complaints through social media. There are seventeen categories associated with these complaints and include such categories as poor quality, not as described on-line, price too high and slow delivery. When creating a chart to determine which of these categories represents the most frequent problem, it will be necessary to draw a ____________________. histog
Taguchi Diagram
Which of the following Six-Sigma tools is not used in the problem finding phase
Taguchi Diagram
The center line in a statistical quality control chart represents the ____________ .
Target
A Value Stream Map also called a Process Flow Chart is used in Six-Sigma to analyze the variability of a process.
True
A Value Stream Map includes symbols for process steps and delays.
True
A control chart is used to monitor a process mean by collecting sample means from that process on a regularly scheduled basis. The horizontal or "X" axis on this chart will represent the mean value of the sample while the vertical or "Y" axis will represent time measured in hours, days or weeks.
True
A statistical control chart can be used to monitor process waste.
True
An ANOVA test determines if there is a significant difference across the means of more than two samples, but it does not tell you if one mean is more significant than the other.
True
If the coefficient of an independent variable in a regression equation is 35 and the p-value for that coefficient is 0.001, the coefficient is significant.
True
If the critical value of p is p= 0.05 and the calculated value of p is p=0.005, the null hypothesis should be rejected.
True
It would be reasonable to expect that a hospital surgical procedure be designed, managed and controlled to ensure a one sigma limit for errors.
True
Lower and Upper Specification Limits must be contained within Lower and Upper Control Levels.
True
Nonparametric tests such as the One Sample Sign Test are used when the assumption of normality cannot be assured.
True
Process Maps display a more detailed view of a process than do Value Stream Maps.
True
Process means are determined by the capability of the process itself and not by the positions of the LCL and UCL.
True
Regardless of the product or process, it is advisable to set a six-sigma limit to ensure acceptable product or service quality.
True
The Distribution of Sample Means expresses the way in which sample means taken from a population and of a given sample size are distributed around the population mean.
True
The Root Cause refers to the process of drilling down through data to find the fundamental or most basic cause of a problem.
True
The Standard Error of the Mean will exactly equal the Standard Deviation of the population when the sample size is one.
True
The UCL and LCL can be set at any distance from the target or centerline, however, when they are set too far away, and if the process output level does shift, this shift may not be detected for quite some time. The reason for this is that even when the process does shift, the sample means from the shifted process may still fall within these wide UCL and LCL limits.
True
The advantage of designing a process with six sigma limits is that no defects will be produced by the process unless the process goes out-of-control.
True
The average time it takes to repair headphones at a factory repair center is 90 hours with a standard deviation of 10 hours. To monitor this process daily, samples of 15 headphones are taken and the mean time computed. Today, the mean time was 84.5 hours. Suppose a similar sample of 15 headphones was undertaken shortly after the first sample was taken. The mean of both samples would be expected to be the same if the process is in-control.
True
The calculated p-value in a One Sample t Test represents the probability of observing a sample mean this far from the target mean.
True
The concept behind the use of a control chart to monitor a process mean is that sample means taken from the process vary around the process mean. If the sample mean varies too far from the process mean, the process mean may have shifted and is in need of adjustment. In other words, the process may no longer be in-control
True
The intercept in a simple linear regression model represents the point at which the regression line crosses the X axis.
True
The null hypothesis tests for what it is we would like to prove
True
The output from a process summarized by its process mean can not be changed by adjusting the target level. The process mean itself must be changed by re-engineering the process or re-training staff.
True
To monitor variation in a process, a sample is taken, the range calculated, and the range plotted on a quality control chart. As long as the sample result falls within the UCL and LCL, the variation associated with this process would be considered in-control.
True
Upper and Lower Control Limits for a manufacturing process have been set at a level such that the process is expected to produce 250 defects per million outcomes. If the Upper and Lower Specifications are set outside these limits then customers will receive even fewer defects per million outcomes.
True
When a sample size increases the Standard Error of the Mean decreases.
True
When designing a process for an emergency room system at a hospital and that system must accommodate patients within a maximum allowable waiting time, it is not necessary to include a lower specification limit in the process control chart.
True
Whenever a process is designed - regardless of industry or functional area within a business, regardless of whether it is in health care or manufacturing - a Six-Sigma control system should be considered to ensure that process goals are met.
True
A process output target or centerline is positioned below the ___ on a control chart
Upper Control Limit
A P-Chart is used to monitor ____________ data.
Variable
An S-chart is used to monitor process ___ when the size of the sample N is greater than 12
Variation
The standard deviation measures the ___ in a dataset
Variation of data
A call center has received many emails form customers who complain that they have to wait too long before reaching a representative. The company has taken steps to improve the process and would like to establish a process control system so that they could monitor the length of time it takes to reach a representative. They plan to take two samples each day. Each sample will include 10 calls. Which of the following charts would be appropriate?
X-bar and R-chart
Which of the following defines the relationship between process inputs and outputs?
Y=f(X)
If the Upper Control Limit and Lower Control Limit were set at plus and minus one standard deviation from the mean and the operational process is considered to be in control, which of the following would be true.
about 68 percent of the outcomes would be expected to occur outside the UCL and LCL
When manufacturing a computer chip, a sample of twenty chips is tested daily to determine if the process is in-control. A quality control chart will be designed to display the number of defects produced per sample. Which of the following is not absolutely necessary when designing the chart.
all of the above are absolutely necessary.
The Taguchi Loss Function suggests that _______________ .
as the mean output of a process varies farther and farther away from its target the losses to a company grow larger and larger
A normal distribution can be described as _______________ .
bell shaped and symmetrical
When setting the LCL and UCL positions on a control chart it will be necessary to balance the costs associated with ___________ errors.
both Alpha and Beta
In which of the following situations would it be most appropriate to design a process that meets the Six-Sigma standard?
cellphone manufacturing
A Risk Priority Number, RPN, is used to determine the ____________________ .
consequences or significance of a failure
The Cost of Poor Quality, also referred to by the acronym COPQ, refers to the
costs that would disappear if the process delivered perfect products and services
Which of the following establishes the measurable goals that guide steps and outcomes in Lean Six-Sigma projects?
deliverables
The term Value-Added in Lean refers to ____________________.
delivering value for a product or service from the customers perspective
As the sample size increases, the variation associated with the distribution of sample means __________________.
does not change
The purpose of Poka-Yoke is to ______________ .
eliminate the possibility that an error will occur
It is not necessary to test the significance of the independent variables in a regression equation as long as the regression equation itself is significant.
false
A software developer has been too-late-to-market on several occasions; competitors have introduced apps much quicker and as a result have captured a larger market share. The developer is concerned that the major factor in slowing this process is the time it takes for product developers to design and communicate the functionality needed to software designers. But, in addition, there are just too many times when each stage in the development process must be approved by managers before the process can continue. Which of the following tools could be most useful in the early stages of studying this development process with an objective to shorten time-to-market?
fishbone diagram
Which of the following is a tool used to uncover the root-cause of a problem?
fishbone diagram
Many organizations obtain their inputs though a supply chain. Consider the supply chain for a plant that assembles industrial pumps. Parts are ordered from suppliers across the world and assembled in Mexico. The Mexican plant requires that suppliers arrange shipments so that parts arrive just as they are needed. If they arrive too early they must stored in inventory. It is costly to store them, but if too many are stored they may become obsolete as new models are designed that use different parts. As a consequence, inventory storage when analyzed from the perspective of a lean supply chain like the one described here would be considered a ______________ .
interactive activity that links the supply chain to assembly operations
An X-bar chart is used to monitor process means when sample sizes are ____
large or small
The average time it takes to process a mortgage application at a mortgage company is five days, but this can vary considerably. Some applications can take as long as eight days. To improve customer service, reduce the time it takes to process an application, and reduce variability in processing time, it would be advisable to undertake which of the following projects?
lean
Which of the following two statistics is used to describe a normal distribution?
mean, standard deviation
The two fundamental issues addressed by Six-Sigma include the monitoring of process _____________ and process _____________.
mean, varation
A Two Sample t Test assumes that the population from which samples will be drawn is
normally distributed
The Nonparametric equivalent to the parametric hypothesis test for the One Sample t Test is
one sample t test
A process that is considered to be ______________ is one where: sample outcomes over time are distributed around a target value or centerline; the variation of process output is randomly distributed about this target; and the sample outcomes are within the lower and upper control limits.
optimized
When manufacturing a computer chip, a sample of 50 chips is tested. The test classifies them as good or bad. The percent bad is plotted on the control chart. Which of the following control charts should be used?
p chart
A ___________ error occurs when the process mean is stable and in-control but an output result has occurred above the UCL or below the LCL. So, in this situation a false out-of-control signal has occurred.
process mean
An X-Bar chart monitors
process sample means
Which of the following represents the statistic that is plotted on an S-Chart?
sample standard deviations
A process is in-control and stable. What type of variation would be expected?
special cause variation
Which of the following is necessary to create an R-Chart?
standard variation
When Special Cause variation is suspected, which of the following steps should be taken?
stop the process identify the special cause and eliminate it
In an R-Chart, the range is used as an estimate of the standard deviation.
true
When designing a test of hypothesis a one-tailed test must always be used when sample sizes are small.
true
when the mean of a normal distribution is 10 and its standard deviation is two, ninety-five percent of the data points within the distribution will fall between plus and minus ______ standard deviations from the mean.
two
When the difference between the means of more than two samples must be tested, and the assumption of normality is met, which of the f
two sample t test
Which of the following is true about the root cause of a problem?
when removed it is very likely to eliminate the problem