A department of Delta Company incurred the following costs for the month of June. Variable costs, and the variable portion of mixed costs, are a function of the number of units of activity:

Activity level in units $5,000$

Variable costs $ $9,750$

Fixed costs $31,000$

Mixed costs $20,140$

Total costs $ $60,890$

During July, the activity level was $8,800$ units, and the total costs incurred were $$70,000.$

Required:

Calculate the variable costs, fixed costs, and mixed costs incurred during July.

Use the high$$low method to calculate the cost formula for mixed cost.