[EX02-072] A constant objective in the manufacture of contact lenses is to improve those features that affect lens power and visual acuity.

One such feature involves the tooling from which lenses are ultimately manufactured. The results of initial process development runs were examined for critical feature X. The resulting data are listed here:

0.026 0.027 0.024 0.023 0.034 0.035 0.035 0.033 0.034 0.033 0.032 0.038 0.041 0.041 0.021 0.022 0.027 0.032 0.023 0.023 0.024 0.017 0.023 0.019 0.027 Source: Bausch & Lomb (variable not named and data coded at B&L’s request)

a. Draw both a dotplot and a histogram of the critical feature X data.

b. Find the mean for critical feature X.

c. Find the median for critical feature X.

d. Find the midrange for critical feature X.

e. Find the mode, if one exists, for critical feature X.

f. What feature of the distribution, as shown by the graphs found in part

a, seems unusual?

Where do the answers found in parts

b, c, and d fall relative to the distribution? Explain.

g. Identify at least one possible cause for this seemingly unusual situation.