Ray Corporation, a small manufacturing firm, wants to establish a pension fund for its 10 employees who range from 28 to 51 years of age. Ray wants each employee who retires from the firm at age 65 to receive an annual pension on the retirement date that is 70 percent of the employee’s annual wage at retirement. What factors must Ray Corporation take into consideration to determine how much the firm must contribute to the pension fund each year to meet the terms of its retirement plan?