Six Sigma Six Sigma Certifications LSSMBB Questions & Answers

• Question 181:

  How do you check that a regression model is valid?

  A. Residuals are normally distributed

  B. Residuals are independent

  C. Residuals have constant variation

  D. All of the above

  Correct Answer: D

• Question 182:

  What can you conclude if the Sum of Squares Error is larger than Sum of Squares for the Model?

  A. R-Squareisgreaterthan0.5

  B. R-Square is less than 0

  C. R-Square is equal to 1

  D. R-Square is less than 0.5

  Correct Answer: D

• Question 183:

  In analyzing some data, you first try multiple linear regression with all the factors and with interactions

  (example: Factor A times Factor B is interaction AB)

  You obtain a multiple regression equation of the form:

  Response = 15 + .13 A - .30 B - .02 C - .00001 AB + .0000004 AC - .00000013 BC +.000000 ABC.

  The p-values for most of the factors and interactions are between 0 and .05, except interactions BC and

  ABC, which have p-values between .4 and .9.

  Which of the following approaches might be appropriate to simplify the equation?

  A. Drop all factors with negative coefficients.

  B. Drop factors BC and ABC and rerun the multiple linear regression.

  C. Drop factors B and C and rerun the multiple linear regression.

  D. Drop factors B and C and rerun the multiple linear regression.

  Correct Answer: B

• Question 184:

  When evaluating residuals from a regression model, a Black Belt discovers that she has outliers in the data. What is best course of action for the outliers?

  A. Ignore them. They should not impact the model.

  B. Omit them.

  C. Explore the source of the outlier.

  D. Transform the independent variable and re-fit the model.

  Correct Answer: C

• Question 185:

  Which of the following statements is NOT true regarding the Simple Regression formula?

  A. Y = the response variable

  B. X = the input variable

  C. 1 is the intercept

  D. 0 and 1 are the model coefficients to be estimated in the data

  Correct Answer: C

• Question 186:

  In a regression analysis, model assumptions are validated using which of the following?

  A. The ANOVA table

  B. A plot of X versus predicted/fitted Y

  C. Chi-square statistic

  D. Residual diagnostics

  Correct Answer: D

• Question 187:

  For a multiple regression model, the R2 is the parameter that:

  A. Represents the fraction of total variation explained by the model

  B. Explains the strength of only one of the inputs in the model

  C. Explains if the input factor causes the output response

  D. Quantifies the slope of the line in the model

  Correct Answer: A

• Question 188:

  While checking regression model assumptions, an engineer generates the following plot of residuals versus predicted Y.

  Which of the actions below is the most appropriate next step?

  

  A. Transform the response and re-fit the model

  B. Make additional runs, collect additional data and re-fit the model

  C. No transformation is required for this type of pattern

  D. Transform the independent variable and re-fit the model

  Correct Answer: A

• Question 189:

  The following is the best description for the purpose of a process map:

  A. It is a tool used only after a Six Sigma project is completed

  B. It is a tool to convert customer requirements to a set of measurable technical requirements with target values.

  C. It is a tool for identifying alternative solutions or concepts

  D. It is a tool used to identify all major steps, outputs, and inputs to look for potential causes of a problem.

  Correct Answer: D

• Question 190:

  Given repeatability RPT =4 and reproducibility RPD = 3, calculate precision MS

  A. MS = 3

  B. MS = 7

  C. MS = 25

  D. MS = 5

  Correct Answer: D