Final answer:
Belton electronics needs to account for a total of 91 service-years in their amortization calculations using the years-of-service method.
Step-by-step explanation:
To calculate the total service-years Belton needs to account for in their amortization calculations using the years-of-service method, we need to consider the percentage of employees leaving the company each year. According to the given information, 10% of the employees will leave in the first year, 25% in the second year, 40% in the third year, and 25% in the fourth year.
We can calculate the number of service-years for each year as follows:
The total service-years Belton needs to account for is the sum of the service-years for each year: 12 + 27 + 32 + 20 = 91 service-years. Therefore, the correct answer is 91 service-years.