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: During July, the activity level was 7,800 units, and the total costs incurred were $69,500. Required: a. Calculate the variable costs, fixed costs, and mixed costs incurred during July. b. Use the high-low method to calculate the cost formula for mixed cost. Complete this question by entering your answers in the tabs below. 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. Note: Do not round intermediate calculations and round your answers to 2 decimal places