70. Put a lid on it! The supplier is considering two changes to reduce to 1% the percentage of its large-cup lids that are too small. One strategy is to adjust the
mean diameter of its lids. Another option is to alter the production process,
thereby decreasing the standard deviation of the lid diameters.
a. If the standard deviation remains at g = 0.02 inch, at what value should the
supplier set the mean diameter of its large-cup lids so that only 1% are too
small to fit?
b. If the mean diameter stays at y = 3.98 inches, what value of the standard
deviation will result in only 1% of lids that are too small to fit?
c. Which of the two options in parts (a) and (b) do you think is preferable? Justify
your answer. (Be sure to consider the effect of these changes on the percent of
lids that are too large to fit.)