SSGI- LEAN SIX SIGMA – GREEN BELT STUDY GUIDE CHAPTER 13-15
QUIZZES
CHAPTER 13
1. The greater is the variation of data around the mean, the smaller will be the
standard deviation.
False
2. The standard deviation represents the extent of variation in a
distribution. True
3. When the standard deviation is large, the spread of the data around a mean is larger
than if the standard deviation were small.
True
4. Two statistics that define a normal distribution are the and the .
mean, standard deviation
5. The mean represents the centralness of a
distribution True
6. Many distributions describing natural processes such as IQ (Intelligence Quotient)
or height can be classified as normal distributions.
True
7. In a normal distribution most of the data items cluster toward the ends or tails of
the distribution.
False
8. Normal distributions have special properties that specify the percent of observations
or data that fall within a specified number of standard deviations from the mean.
True
9. Sixty- Eight (assume rounding) percent of the observations or data in a normal
distribution fall between the mean and plus or minus one standard deviation from
the mean.
True
10. Ninety-five percent of the observations in a normal distribution fall above the
mean. False
11. Using the special properties of the normal distribution, 99.7 percent of the data in
a normal distribution will fall between the mean and plus or minus three standard
deviations from the mean.
True
12. The data or observations that fall under the normal distribution between plus one and
plus two standard deviations from the mean is 13.6 percent.
True
13. The percent of the data or observations between minus one standard deviation from
the mean and minus three standard deviations from the mean is 60 percent.
False
14. The special properties of the normal distribution apply to a distribution whether or not
it is normally distributed.
False
, 15. The number of data points or observations beyond plus and minus six standard
deviations from the mean would be much less than one percent.
True
16. A Z value of ±2 will include percent of the observations under the normal
distribution.
95
17. The average wait time at call center is 7 minutes with a standard deviation of 1 minute.
A customer has called and has waited 10.5 minutes. What is the Z value?
3.5
18. The Z table tells us that the area under the normal curve to the left of Z value of 1.5
is 0.9332. The area under the normal curve between plus and minus Z=1.5 is .
0.8664 ; 1.000 - 0.9332 = 0.0668. Then subtract this from 0.9332. ). The answer is
.9332 -
0.0668 = 0.8664
19. If the Z value is zero, then percent of the area under the curve is less than the
mean.
50
20. When the Z Value is +3 which of the following best represents the area under the
normal curve to the right of the Z value?
Less than 1%
21. The binomial distribution represents discrete processes, those that have more than
two possible outcomes.
False ; Binomial is for discrete processes with only two outcomes.
22. The probabilities associated with tossing a coin wold be represented by a
distribution.
Binomial
23. The probability of getting exatly two heads in two tosses of a coin would be called a
probability.
Binomial
24. The Poisson distribution focuses on the number of discrete occurrences over a
defined interval.
True
25. If you need to determine the probability that exactly five calls will arrive at the call
center between 8 and 9 AM today, what probability distribution could be used to provide
the answer.
Poisson
26. A t distribution is used to determine probabilities when the sample is
small. True
27. A t-Test is used to determine the difference between two samples when the sample
sizes are small.
True
28. A Chi Square distribution is used to evaluate the difference between
counts True
29. Chi Square tests are used when count data is presented in a table.
Contingency
30. F distributions are used to compare .
Variances
QUIZZES
CHAPTER 13
1. The greater is the variation of data around the mean, the smaller will be the
standard deviation.
False
2. The standard deviation represents the extent of variation in a
distribution. True
3. When the standard deviation is large, the spread of the data around a mean is larger
than if the standard deviation were small.
True
4. Two statistics that define a normal distribution are the and the .
mean, standard deviation
5. The mean represents the centralness of a
distribution True
6. Many distributions describing natural processes such as IQ (Intelligence Quotient)
or height can be classified as normal distributions.
True
7. In a normal distribution most of the data items cluster toward the ends or tails of
the distribution.
False
8. Normal distributions have special properties that specify the percent of observations
or data that fall within a specified number of standard deviations from the mean.
True
9. Sixty- Eight (assume rounding) percent of the observations or data in a normal
distribution fall between the mean and plus or minus one standard deviation from
the mean.
True
10. Ninety-five percent of the observations in a normal distribution fall above the
mean. False
11. Using the special properties of the normal distribution, 99.7 percent of the data in
a normal distribution will fall between the mean and plus or minus three standard
deviations from the mean.
True
12. The data or observations that fall under the normal distribution between plus one and
plus two standard deviations from the mean is 13.6 percent.
True
13. The percent of the data or observations between minus one standard deviation from
the mean and minus three standard deviations from the mean is 60 percent.
False
14. The special properties of the normal distribution apply to a distribution whether or not
it is normally distributed.
False
, 15. The number of data points or observations beyond plus and minus six standard
deviations from the mean would be much less than one percent.
True
16. A Z value of ±2 will include percent of the observations under the normal
distribution.
95
17. The average wait time at call center is 7 minutes with a standard deviation of 1 minute.
A customer has called and has waited 10.5 minutes. What is the Z value?
3.5
18. The Z table tells us that the area under the normal curve to the left of Z value of 1.5
is 0.9332. The area under the normal curve between plus and minus Z=1.5 is .
0.8664 ; 1.000 - 0.9332 = 0.0668. Then subtract this from 0.9332. ). The answer is
.9332 -
0.0668 = 0.8664
19. If the Z value is zero, then percent of the area under the curve is less than the
mean.
50
20. When the Z Value is +3 which of the following best represents the area under the
normal curve to the right of the Z value?
Less than 1%
21. The binomial distribution represents discrete processes, those that have more than
two possible outcomes.
False ; Binomial is for discrete processes with only two outcomes.
22. The probabilities associated with tossing a coin wold be represented by a
distribution.
Binomial
23. The probability of getting exatly two heads in two tosses of a coin would be called a
probability.
Binomial
24. The Poisson distribution focuses on the number of discrete occurrences over a
defined interval.
True
25. If you need to determine the probability that exactly five calls will arrive at the call
center between 8 and 9 AM today, what probability distribution could be used to provide
the answer.
Poisson
26. A t distribution is used to determine probabilities when the sample is
small. True
27. A t-Test is used to determine the difference between two samples when the sample
sizes are small.
True
28. A Chi Square distribution is used to evaluate the difference between
counts True
29. Chi Square tests are used when count data is presented in a table.
Contingency
30. F distributions are used to compare .
Variances
