Can you please explain how you got each answer so I can understand the concepts??

Required information [The following information applies to the questions displayed below.] Patel and Sons Inc. uses a standard cost system to apply factory overhead costs to units produced. Practical capacity for the plant is defined as 54,600 machine hours per year, which represents 27,300 units of output. Annual budgeted fixed factory overhead costs are $273,000 and the budgeted variable factory overhead cost rate is $3.50 per unit. Factory overhead costs are applied on the basis of standard machine hours allowed for units produced. Budgeted and actual output for the year was 21,000 units, which took 43,600 machine hours. Actual fixed factory overhead costs for the year amounted to $262,600 while the actual variable overhead cost per unit was $3.40. Based on the information provided above, what was (a) the variable overhead spending variance for the year, and (b) the variable overhead efficiency variance for the year? Indicate whether each variance was favorable (F) or unfavorable (U). (Do not round intermediate calculations. Round your final answers to the nearest whole dollar amount.) (a) Spending variance (b) Efficiency variance Favorable Unfavorable