Propeller Inc. plans to manufacture a newly designed high$-$technology propeller for airplanes. Propeller forecasts that as workers gain experience, they will need less time to complete the job. Based on prior experience, Propeller estimates a $70\%$ cumulative average time learning curve and has projected the following costs.

Cumulative Number Manufacturing Projections

of Units Produced Average Cost Per Unit Total Costs

$1$ $$20,000$ $$20,000$

$214,00028,000$

a$.$ If Propeller manufactures four propellers, what would the total manufacturing costs be$?$

$Answer $1$

b$.$ If Propeller manufactures eight propellers, what would the total manufacturing costs be$?$

$Answer $2$

c$.$ Calculate the cumulative average cost of producing the eighth propeller as a percentage of the cost

of producing the first propeller.

Numerator Denominator Result

Percentage Answer $3$

$-$: Answer $4$

$=$