The Jefferson County School Board has approved a 3.4 property tax increase.The increase was proposed in light of dwindling state and federal funding. It will generate about $17 million for the district, and cost homeowners about $23 for every $100,000 their houses are worth.The revenue will be used to support the district's dozens of new assistant principals and updates to the JCPS transportation plan.The board can levy tax increases of up to 4 percent each year. Last year, the board approved a fraction of a cent increase.Additional reporting by Devin Katayama