Goslin Manufacturing Company set its standard variable manufacturing cost at $21 per unit of product. the company planned to make and sell 4. 700 units of product during 2012. More specifically, the master budget called for total variable manufacturing cost to be $98, 700. Actual production during 2012 was 4, 800 units, and actual variable manufacturing costs amounted to $101, 540. the production supervisor was asked to explain the variance between budgeted and actual cost ($101, 540 - $98, 700 = $2, 840). the supervisor responded that she was not responsible for the variance that was caused solely by the increase in sales volume controlled by the marketing department. Determine the flexible budget variance, and indicate the effect of the variance by selecting "Favorable", "Unfavorable", or "None" (No effect) (i. e. . zero variance). (Input the amount as positive value. Leave no cell blank - be certain to enter "0" wherever required. Omit the "$" sign in your response. ) Flexible budget variance $