Gumchara Corporation reported the following information with respect to the materials required to manufacture amalgam florostats during the current month. Standard price per gram of materials $ 4 Standard quantity of materials per amalgam florostat 5 grams Actual materials purchased and used in production 6,000 grams Actual amalgam florostats produced during the month 1,000 units Actual cost of materials purchased $ 18,000 Normal monthly output 900 units a. Determine Gumchara's materials price variance. b. Determine Gumchara's materials quantity variance. c. Will Gumchara's overhead volume variance be favorable or unfavorable