For the following scenario, determine if the numbers in boldface type are statistics or
parameters.
(a) A company manufactures cardboard containers for packaging frozen fruit juices.
The manufacturing process forms the containers by joining cardboard stock to a
metal bottom. The container can be inspected to determine if there might be leaks
along the cardboard seam or where the metal bottom is attached. It is known from
long experience that 18% of cans produced by this process are defective. A random
sample of 50 cans was selected from the production process on Monday and it was
found that 12% of the selected cans were defective. Because this seemed to indicate
an improvement, another sample was selected of the same size on Tuesday and in
it there were 21% defective cans.
(b) A carload of ball bearings has a mean diameter 2.5003 centimeters. This is within
speci cations by the purchaser. By chance, an inspector chooses 100 bearings from
the lot that have mean diameter 2.5009 cm. Because this is outside the speci ed
limits, the lot is mistakenly rejected.