During February the Mossman Engineering Company's costing system reported several variances that the production manager was surprised to see. Most of the company's monthly variances are under $125, even though they may be either favourable or unfavourable. The following information is for the manufacture of garage doors, its only product: 1. Direct materials price variance, $800 unfavourable. 2. Direct materials efficiency variance, $1800 favourable. 3. Direct manufacturing labour price variance, $4000 favourable. 4. Direct manufacturing labour efficiency variance, $600 unfavourable. Required: a. Provide the manager with some ideas as to what may have caused the price variances. b. What may have caused the efficiency variances