On January 1, 2020, Tecnix. has a beginning inventory of 5,000 keyboards. Elizabeth estimates it will sell 18,000 units during the first quarter of 2020 with a 5% increase in sales each quarter. Tecnix policy is to maintain an ending inventory equal to 25% of the next quarter's sales. Each keyboard costs $190 and is sold for $250. How many units should they produce during the first quarter of 2020