James Manufacturing had the following information available for July:

Actual Results Flexible Budget Variance Flexible Budget Sales Activity Variance Master Budget

Units $14,600?9,200$ U $?$

Sales revenue $?$ $ $14,600$ F $???$

Less:

Variable manufacturing costs $ $103,750$ $ $107,000?$ $ $205,800$

Variable marketing and administrative $?$ $ $4,050$ U $?$ $ $4,800$ F $ $31,600$

Contribution margin $ $55,200??$ $ $6,800$ U $?$

What was James$$s activity variance for variable manufacturing costs?