Uncle Wang participated in the rural medical insurance in the county, and the clauses stipulated that the compensation line for farmers’ medical expenses in hospital was 400 yuan for county-level hospitals, and 45% of the part above the threshold was compensated. This year, Uncle Wang fell ill and was hospitalized in the County People's Hospital for 15 days, with a total medical expenses of 8,200 yuan. According to regulations, how much should Uncle Wang pay?
王大伯参加了县农村医疗保险，条款规定：农民住院医疗费补偿起付线，县级医院400元，在起付线以上的部分按45%补偿．今年王大伯生病在县人民医院住院治疗15天，共计医药费8200元．按规定王大伯应付多少元？
<gadget id="calculator">8_200 - 400</gadget>
<output>7_800</output>

<gadget id="calculator">45 / 100</gadget>
<output>9/20 = around 0.45</output>

<gadget id="calculator">7_800 * (9/20)</gadget>
<output>3_510</output>

<gadget id="calculator">8_200 - 3_510</gadget>
<output>4_690</output>

<result>4_690</result>