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

PROBLEM

Willem was reviewing his former colleague's calculation for unit production time 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 learning curve observed are provided here.

Expected time to make third unit

Expected time to make fourth unit

Learning curve observed

$33\mathrm{.}85$ minutes

$32\mathrm{.}40$ minutes

$90\%$