# Chapter 7 Flashcards Preview

## Lean Six Sigma Primer > Chapter 7 > Flashcards

Flashcards in Chapter 7 Deck (48)
1
Q

A

a. An appropriate product development prosess

2
Q

7.2 In which of the following area of variation in multi-vari analysis would normally reflect piece-to-piece or batch-to-batch variation?

A

b. Cyclical

3
Q

7.3 If the plating time of a tube increases as the inside diameter decreases, then the correlation coefficient for the inside diameter vs plating time would be

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b. between 0 and -1

4
Q

7.4 How is the level of significance defined?

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a. The probability of rejecting a null hypothesis when it is true

5
Q

7.5 A randomly selected sample of bicycle helmets was tested for impact resistance. Given the data results below, what is the 95% confidence interval for the mean?

A

c. 276 (+/-) 2.94 g

E=Z(a/z) [S/(n)^1/2]

6
Q

7.6 A p-value is used in many statistical calculation. It can be described as:

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b. Containing an extreme test statistic probability value as obtained from the sample data

7
Q

7.7 An F distribution most closely resembles

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b. A chi-square distribution

8
Q

7.8 From a statistical standpoint, the sample size for hypothesis testing depends on:

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a. The required type l and type ll risks

9
Q

7.9 When a problem solving team applies the 5 why technique, they are attempting to:

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d. Determine the root cause of the problem

10
Q

7.10 Non-value added activities on the factory floor are most clearly controlled by the elimination of

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b. Muda

11
Q

7.11 Which of the following statements concerning the coefficient of simple linear correlation, r, is true?

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c. r=0.76 has the same predictive power as r= -0.76

12
Q

7.12 The determination of temporal variation in multi-vari charting means

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b. Variation over time

13
Q

7.13 In a single factor analysis of variance, the assumption of homogeneity of variances applies to:

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a. The variances within the treatment groups

14
Q

7.14 A company has just installed a new computer data entry system and the new input error rates must be determined. Management requires the error rate to be within 0.5%, at a 95% confidence level. What sample size is necessary if the population standard deviation is 1.2%?

A

d. 23
n=[Z^2x sigma^2]/E^2
=[(1.96)^2 x (.012)^2]/(.005)^2
=22.13=23

15
Q

7.15 Given that random samples of process A produced 10 defective and 30 good units, while process B produced 25 defectives out of 60 units. Using the chi-square test what is the probability that the observed value of chi-square could result under the hypothesis that both processes are operating at the same quality level?

A

b. Between 5% and 10%

16
Q

7.16 The correlation coefficient for test #1 equals -0.89, and the correlation coefficient for test #2 equals 0.79. Assuming the tests are in different subject areas, which of the following statements is true?

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a. Both tests show a strong correlation

17
Q

7.17 What inference test compares observed and expected frequencies of test outcomes?

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b. Chi-square test

18
Q

7.18 In order to calculate the confidence interval for the mean for a small sample, what must be known?

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d. The average, standard deviation, and appropriate t value

19
Q

7.19 An analysis of variance (ANOVA) is used to analyze the data gathered in an experiment. One-way ANOVA implies that this tool deals with:

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b. Independent samples

20
Q

7.20 Which forms of transportation and storage are considered muda?

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a. Conveyer belts and fork trucks

21
Q

7.21 Which of the following statements concerning statistical inference is true?

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a. The confidence interval is a range of values which may include the true population value

22
Q

7.22 What is the principal advantage of multi-vari charting?

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c. It assists in the breakdown of components of variation

23
Q

7.23 In one-way ANOVA, how is the SSE (the experimental error sum of squares) usually determined?

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b. By dividing SST by the total DF

24
Q

7.24 A string tension gauge is used to validate settings on a tennis racket stringing machine. What are the 90% confidence limits for the estimated true values of the string tension? Measurements: 57, 56, 60, 62, 55, & 59

A
```c. 60.34 pounds, 56.00 pounds:
Mean= 58.17
S=2.64
n=6
t (from table) =2.015
E=(+/-)t [S/(n^2)]```
25
Q

7.25 Given a coefficient of determination of 0.85, which of the following is true?

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b. 85% of the variability is explained by the regression model

26
Q

7.26 Ratios of two variances drawn from the same normal population are described by which one of the following distributions?

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a. F

27
Q

7.27 The opposite of an alpha risk in hypothesis testing is called

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c. Level of confidence

28
Q

7.28 Which table value is normally used to place a confidence interval on the slope of a line in simple linear regression?

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a. t

29
Q

7.29 Which test statistic must be known in order to compute a confidence interval for variation?

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a. Chi-square value

30
Q

7.30 Which of the following is considered muda?

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c. Reshaping a die after installation

31
Q

7.31 Identify the subjective root cause analysis tool from the options below:

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a. 5 whys

32
Q

7.32 A small change truly exists between a current process and an experimental process. However, an insufficient sample size is collected to determine this difference. What type of error would result?

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a. A type ll error

33
Q

7.33 What is the Z value needed to conduct a two-tail test in a statistical inference problem, specifying a 90% level of confidence?

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c. 1.65

34
Q

7.34 If a multi-vari chart shows that 60% of variation is within piece, 25% of variation is piece-to-piece and 10% of variation occurs over time, what would be the indicated improvement action sequence?

A

d. Positional, cyclical, temporal

35
Q

7.35 The current process produces 50 units per shift. A new process produced 60 units per shift, for 10 consecutive shifts. The highest shift was 64 units and lowest shift during the trail was 44 units. What what level of confidence can one say the process has changed?

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d. >99& confidence

36
Q

7.36 Refer to the following partial ANOVA table. what are the missing values?

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a. 450, 1050, 30

900/2=450, 2100/2=1050, 300/10= 30`

37
Q

7.37 A correlation coefficient of +0.95 for 2 variables, x & y, means that:

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a. There is a strong linear relationship between x &y

38
Q

7.38 If 4 inspectors were evaluated, for the detection or non-detection of a defect in 20 samples, how many degrees of freedom would be used to determine the critical chi-square value?

A

d. 3

(1) (3) =3

39
Q

7.39 A product was yielding 90% recovery before an improvement was made. To determine if a 2% change has been made at the 95% confidence level, what sample size should be taken?

A

c. 864

40
Q

7.40 Which of the following characterize the muda of waiting?

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c. Uneven schedule

41
Q

7.41 If the 90% confidence for the mean is 181.3 to 203.8, which of the following statements is correct?

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d. None of the above

42
Q

7.42 The probabilistic regression model for any particular observed value of Y contains a term Bo which represents?

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a. The Y-axis intercept, when X=0

43
Q

7.43 Three machines are being evaluated in a one-way ANOVA. A total of 16 trials have been conducted. How much degrees of freedom are available to evaluate the error term?

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b. 13

44
Q

7.44 A multi-vari chart indicates
15% within piece variation
65% piece-to-piece variation
10% over time variation

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c. Cyclical, positional. temporal

45
Q

7.45 Which of the following confidence interval calculations require the use of Z table values

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a. Large sample means and proportion confidence intervals

46
Q

7.46 If the mean for each of the treatment groups in an experiment were identical, the F ratio would be

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b. 0

47
Q

7.47 For a linear correlation, the total sum of squares equal 1,600 and the total sum of squared errors equals 1,000. What is r^2

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c. 0.375

48
Q

7.48 Identify the element that is associated with excess inventory?

A

a. Storage space and transportation vehicles