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: Purchased 170,000 pounds of raw materials at a cost of $9.00 per pound. All of this material was used in production Direct-laborers worked 82,000 hours at a rate of $ 18.00 per hour. Total variable manufacturing overhead for the month was $505,000. Total advertising, sales salaries and commissions, and shipping expenses were $337,000, $505,120, and $128,000, respectively. What is the variable overhead rate variance for march? What amounts of advertising, sales salaries and commissions, and shipping expenses would be included in the company's flexible budget for March? What is the spending variance related to advertising? What is the spending variance related to sales salaries and commissions? What is the spending variance related to shipping expenses