Consider the following sample of observations on coating thickness for low viscosity paint (“Achieving a Target Value for a Manufacturing Process: A Case Study,” J. of Quality Technology, 1992: 22–26):

Assume that the distribution of coating thickness is normal (a normal probability plot strongly supports this assumption).

a. Calculate a point estimate of the mean value of coating thickness, and state which estimator you used.

b. Calculate a point estimate of the median of the coating thickness distribution, and state which estimator you used.

c. Calculate a point estimate of the value that separates the largest 10% of all values in the thickness distribution from the remaining 90%, and state which estimator you used.

d. Estimate P(X < 1.5), i.e., the proportion of all thickness values less than 1.5.

e. What is the estimated standard error of the estimator that you used in part (b)?

Transcribed Image Text:

83 88 .88 1.04 1.09 1.12 1.29 1.31 1.48 149 1.59 62 1.65 .7 1.76 1.83