suppose wanda´s widgets has a fixed proportions production function. it currently delivers 1000 widgets per month to its only customer. currently, wanda´s costs are $2000 per month per machine and $4000 per month per worker. wanda uses 20 machines and 10 workers to produce 1000 widgets each month. if the cost of machines fall to $1600 per month and wanda continues to produce 1000 widgets, what happens to total costs? show this in a graph, using one isoquant and a pair of isocost lines. (Hint: what are the horizontal intercepts of the old and new isocost lines?)