Horn Industries uses a standard cost accounting system and allocates variable manufacturing overhead costs based on machine hours. Here are data regarding Horn's production activity for the month of July: Actual total variable manufacturing overhead costs $11,312 Actual total machine hours 1,600 hours Variable manufacturing overhead rate variance $1,712 unfavorable Variable manufacturing overhead spending variance $2,312 unfavorable What is the standard number of machine hours allowed for July production? 1.450 hours 1,500 hours 1,650 hours O 1.700 hours None of the above