Roberts Enterprises has budgeted sales in units for the next five months as follows: 4,500 units 7,100 units June July August 5,300 units September 6,700 units October 3,700 units Past experience has shown that the ending inventory for each month must be equal to 10% of the next month's sales in units. The inventory on May 31 contained 450 units. The company needs to prepare a production budget for the second quarter of the year. The total number of units to be produced in July is