Answer:
 $73,600
Step-by-step explanation:
A learning curve is a correlation between a learner's performance on a task and the number of attempts or time required to complete the task; this can be represented as a direct proportion on a graph
The last unit will be 22nd unit . 
 
Using learning curve table , 
Time required to build 22nd unit = 3125.49 hours 
 
labour cost to build 22nd unit ( $20 per hour ) = $20 x $3125.49 
labour cost to build 22nd unit = $62509.80 
 
Using learning curve table , 
material and equipment cost to build 22nd unit = $11090.67 
 
Therefore,
 total cost to build the last unit = Labour cost + Material and equipment cost total cost to build the last unit = $62509.80 + $11090.67 
 total cost to build the last unit = $73600.47 
 
Learning rate for labour hours ( L1) = Time for 2nd unit / Time for 1st unit 
Learning rate for labour hours ( L1) = 4500/5000 
Learning rate for labour hours ( L1) = 0.90 
 
Learning rate for material and equipment usage 
Learning rate for material and equipment usage = Material and equipment cost for 2nd item / Material and equipment cost for 1st item 
Learning rate for material and equipment usage = 24000/30000 
Learning rate for material and equipment usage = 0.80 or 80 %