Required information

$[$The following information applies to the questions displayed below.$]$

Preble Company manufactures one product. Its variable manufacturing overhead is applied to production based on direct

labor$-$hours and its standard cost card per unit is as follows:

The planning budget for March was based on producing and selling $24,000$ units. However, during March the company

actually produced and sold $30,600$ units and incurred the following costs:

a$.$ Purchased $170,000$ pounds of raw materials at a cost of $$9\mathrm{.}00$ per pound. All of this material was used in production.

b$.$ Direct laborers worked $68,000$ hours at a rate of $$18$ per hour.

c$.$ Total variable manufacturing overhead for the month was $$512,040.$

What is the labor efficiency variance for March?

Note: Indicate the effect of each variance by selecting $"$F$"$ for favorable, $"$U$"$ for unfavorable, and "None" for no effect $($i$.$e$.,$ zero

variance.$).$ Input all amounts as positive values.