BS plc makes a widget with the following information for the month just ended: The actual materials price was £4.50 per kg. 5,500 widgets were produced The materials price variance was £2,270 unfavourable. The standard quantity of material usage per widget was 3 kgs The actual quantity of material used was 16,000 kgs (a) Calculate the standard material price for a Widget (b) Calculate the material usage variance (c) Explain one possible cause of both the material price and usage variances at ABS plc.