Answer:
a. $2,000 U; $6,000 U
Step-by-step explanation:
Material Mix Variance for X = (Actual Usage in standard proportions - Actual Usage in Actual Proportions) * Standard Price per unit
= ((55000*0.3) - 17000) * $4
= $2,000 Unfavorable
Material Yield Variance for X = (Expected input units in standard proportions - Input units based on Actual output) * Standard Price per unit
= ((55000*0.3) - (50000*0.3)) * $4
= $6,000 Unfavorable