Answer Happy

For samples of 9 observations, a production process has a mean
equal to 100 and a variance equal to 36. If five samples had means
of 102, 93, 98, 101, and 104.
Use the above information to answer the following
questions: (always round to two decimal places):
I. Determine the lower and upper control limits for the
X-bar control chart. The letter associated with the correct
answer is
a) 64 and 136 respectively.
b) 94 and 106 respectively.
c) 108 and 132 respectively.
d) 117 and 123 respectively.
e) None of the above
II. What is the margin of error equal to? The letter
associated with the correct answer is
a) 3
b) 6
c) 12
d) 36
e) None of the above
III. Is the central tendency of process in control?
Explain. The letter associated with the correct answer
is
a) Yes, because all sample means values fall within the control
interval for X-bar
b) Yes, because all x values fall within the control interval
for X-bar
c) No, because exactly two sample means fall outside the control
interval for X-bar
d) No, because exactly one sample mean falls outside the control
interval for X-bar
e) None of the above