E$3\mathrm{.}13-$ Using Excel with Learning Curves

PROBLEM

Nillem was reviewing his former colleague's calculation for unit production ime with a learning curve, but he felt like he was missing something. Estimates of the time it would take to make each successive unit and the earning curve observed are provided here.

Expected time to make third unit

$33\mathrm{.}85$ minutes

Expected time to make fourth unit

$32\mathrm{.}40$ minutes

Learning curve observed

$90\%$