.
. Starting Step 2.2
let function f = exp(-b1*metal)/(b2+b3*metal)
pre-fit ultrason = f ...
    for b1 = 0.1 0.1 1 for b2 = 0.1 0.1 1 for b3 = 0.1 0.1 1
.
. Finished Step 2.2: Page Back for Output