Can you please explain how the below is performed?

Problem:

Prepare a monthly flexible selling expense budget fora companywho hassales volumes of $270,000, $350,000, and $480,000, based on the following data:

Sales commissions 7% of sales

Sales manager's salary $62,000 per month

Advertising expense $70,000 per month

Shipping expense 2% of sales

Miscellaneous selling expense $2,500 per month plus 1/2% of sales

looking for the following information for each of the volume amounts (270,000, $350,000, and $480,000)

Sale volume

Variable expense:

Sales Commissions

Shipping expense

Miscellaneous selling expense

Total variable expense

Fixed expense:

Sales manager's salary

advertising expense

miscellaneous selling expense

Total fixed expense

Total selling expense