Lacourse incorporated's inspection costs are listed below: January February March April May June July August Units Produced 438 388 457 472 414 389 464 415 Inspection Costs $6,146 $5,647 $6,361 $6,499 $5,897 $5,650 $6,426 $5,910 A Management believes that inspection cost is a mixed cost that depends on units produced. Using the least-squares regression method, the estimate of the variable component of inspection cost per unit produced is closest to