Lanman, Inc., estimates its hidden external failure costs using the Taguchi loss function. Lanman produces plastic sheets that vary in thickness and grade. For one of its large$-$volume products, it was determined that k $=$ $$40,000$ and T $=0\mathrm{.}31$ inches in diameter. A sample of four units produced the following values:

Unit No$.$ Actual Diameter $($y$)$

$10\mathrm{.}33$

$20\mathrm{.}30$

$30\mathrm{.}29$

$40\mathrm{.}32$