Final answer:
The ratio of the number of years the spouse was employed to the total number of years in the retirement plan can be calculated by dividing the number of years employed by the total number of years in the retirement plan.
Step-by-step explanation:
The ratio of the number of years the spouse was employed to the total number of years in the retirement plan can be calculated by dividing the number of years employed by the total number of years in the retirement plan. Let's say the number of years the spouse was employed is 'x' and the total number of years in the retirement plan is 'y'. The ratio would be x/y.