XYZ company has had some customer complaints regarding dimensional
quality of some of our products. It is inconvenient to remove product from
manufacturing for measurement, so pennies are to be used as a substitute
for testing. Please perform the following tests and return your data
as an attachment to your memo.
Test #1: Repeatability of the measurement
Select a single penny. Each member of the test group is to measure
its diameter 10 times, to the nearest .0001 inch. For each operator,
determine the mean and standard deviation of the diameter. If mean
and standard deviation are the same between members, please explain.
The intention of this test is to indicate the variability of the measurement
method and operators.
Test #2: Diameter of pennies in circulation
It is suspected that pennies wear down as they are carried in hundreds
of people’s pockets, so that most pennies should be smaller than whatever
size they were when manufactured. Each group will be supplied with
30 pennies. Measure the outside diameter to the nearest .0001 inch.
Determine the mean and standard deviation of the sample, and determine
the diameter where 99% of the pennies should be larger, and the diameter
where 99% of the pennies should be smaller. In other words, determine
the limit sizes such that there is a 98% probability that a penny will
be between these limits. While the XYZ Company does not stamp pennies,
by this work we should be able to set appropriate acceptance limits for
our own processes.
Test #3: Standard size of pennies
Go find the stated diameter of pennies at manufacture by the US Mint.
In your memo, provide a bibliographic reference to the source of your data.
(Translation: Be specific about where you found your answer.) |