Beverly Company has determined a standard variable overhead rate of $2.60 per direct labor hour and expects to incur 0.50 labor hours per unit produced. Last month, Beverly incurred 1,000 actual direct labor hours in the production of 2,100 units. The company has also determined that its actual variable overhead rate is $2.40 per direct labor hour. Required: Calculate the variable overhead rate and efficiency variances as well as the total amount of overor underapplied variable overhead. Note: Indicate the effect of each variance by selecting "F" for favorable, "U" for unfavorable, and "None" for no effect (i.e., zero variance)