please write out the formulas for how you arrived to your answers.

U.S. Airfilter has hired you as a supply chain consultant. The company makes air filters for residential heating and air-conditioning systems. These filters are made in a single plant located in Louisville, Kentucky, in the United States. They are distributed to retailers through wholesale centers in 100 locations in the United States, Canada, and Europe. You have collected the following data relating to the value of inventory in the U.S. Airfilter supply chain: QUARTER 1 QUARTER 2 QUARTER 3 QUARTER 4 (JANUARY (APRIL (JULY THROUGH (OCTOBER THROUGH THROUGH MARCH) THROUGH JUNE) SEPTEMBER) DECEMBER) 300 375 Sales (total quarter): United States Canada Europe 75 30 350 60 33 405 75 20 70 15 280 295 340 350 Cost of goods sold (total quarter) 50 40 55 60 Raw materials at the Louisville plant (end-of-quarter) 100 105 120 150 Work-in-process and finished goods at the Louisville plant (end-of-quarter) Distribution center inventory (end-of-quarter): United States Canada Europe 25 10 5 27 11 23 15 30 16 4 5 5 All amounts in millions of U.S. dollars. a) What is the average inventory turnover (quarterly and yearly) for the firm? (5 points) b) If you were given the assignment to increase inventory turnover, what would you focus on? Why? (1 point)