The assumption that the errors or residuals are independent is ...

[imowrer]

The assumption that the errors or residuals are independent is best checked by:
 
  A) looking at a normal probability plot of the residuals.
  B) looking a scatter plot of each x versus y.
  C) looking at a residual plot versus x and checking for curvature.
  D) looking at a plot of the residuals versus time and checking for trends.

Question 2

A company that fills soft drinks into bottles wishes to establish an -chart to monitor the average fill level in the bottles. To do this, the company has taken a series of samples of size n = 4 bottles. The overall average fill is 12.03 ounces.
 
  The average range for the subgroups has been .06 ounces. Based on this information, what is the upper limit of the 3-sigma control limit?A) .729
  B) .0437
  C) 12.09
  D) 12.074

[Bigfoot1984]

Answer to Question 1

A

Answer to Question 2

D