options are ; At maximum, At a minimum, Falling, Rising, Constant. question 15: (1 point) Fill in the blanks: When marginal cost is greater than average variable cost, average variable cost is ____ Question 16: (1 point) Fill in the blanks: When marginal cost equals average variable cost, average variable cost is ____ Question17: (1 point) Fill in the blanks: When marginal cost is less than average variable cost, average variable cost is ____ Question18: (1 point) Fill in the blanks: When marginal cost is greater than average variable cost , marginal product is ____ Question19: (1 point) Fill in the blanks: When average variable cost is at a minimum , marginal cost is ____ Question 20: (1 point) Fill in the blanks: When marginal cost is at the minimum average product is ____ Need explanation of all parts