Answer and Explanation:
The preparation of the flexible manufacturing budget is presented below:
                                               Activity level    
Finished units                 75,600            96,600           117,600
                                                       (75,600 + 21,000)       
Variable costs    
Direct materials($3)	$226,800	$289,800	$352,800
Direct labor ($7)          $529,200	$676,200	$823,200
Overhead ($10)         $756,000       $966,000       $1,176,000
Total variable costs	$1,512000       $1,932,000      $2,352,000
Fixed costs    
Depreciation [($4 ×  1,207,200) ÷  12]	$402,400    $402,400  
$402,400  
Supervision [($1 ×  1,207,200) ÷  12]     $100,600     $100,600   $100,600
Total fixed costs     $503,000           $503,000          $503,000
Total costs            $2,015,000          $2,435,000       $2,855,000
We simply added the total variable and total fixed cost so that the total cost could come and the same is shown above