the perfect tool company (south america division) produced 80,000 saw blades during the year. it took 1.5 hours of labor per blade at a rate of $8.50 per hour. however, its standard labor rate is $8.00. its labor efficiency variance was an unfavorable $40,000. what is perfect's labor rate variance? group of answer choices $60,000 u $57,500 f $57,500 u $60,000 f