Final answer:
Robert Key's monthly paycheck deduction for medical insurance is $189.
Step-by-step explanation:
To calculate Robert Key's monthly paycheck deduction for medical insurance, we first need to determine the total cost of his insurance coverage for the year. Given that his group medical insurance coverage costs $6,480 per year and his employer pays 65% of the cost, we can find the amount he needs to pay. The amount covered by his employer is 65% of $6,480, which is $4,212. Thus, Robert's annual contribution would be $6,480 - $4,212 = $2,268. To find the monthly deduction, we divide this amount by 12 since there are 12 months in a year. Therefore, Robert Key's monthly paycheck deduction for medical insurance is $2,268 / 12 = $189.