The Marshalltown School Board of Monday approved a certified budget during its meeting, a budget which will be sent on to the county in time for an April 15th deadline. If the school district would not receive state supplemental aid the property tax would go up 36 cents to 18 dollars and 69 cents per one-thousand dollars of assessed property tax valuation. However if a state supplemental aid bill passed by the House and Senate is signed by Governor Branstad the tax levy would go down to 17.93 from the present level of 18.33.