The insurance company pays 80% of $4,400:
0.8*4400 = $3520
Therefor the amount Marge pays is 4400 - 3520 = $880
Note however that $4400 is the cost of annual group insurance, so to find how much she pays monthly we need to divide the amount she pays in one year by 12:
880/12 = $73.33 (correct to two decimal places)
