Voters in Dallas County — which includes much of the western Des Moines suburubs — have approved a one-cent local option sales tax for school improvements. That means when a new shopping mall planned in West Des Moines opens, purchases will be subject to the higher tax rate. But voters in the Marshalltown School District voted down a 25-million dollar property tax hike that would have paid for school improvements. The measure needed 60 percent to pass, but got only 55 percent support. School Board president Bob Christiansen says the needs remain, and they hope to submit the issue to Marshalltown-area voters again in six months.Marshalltown superintendent Richard Doyle says he’s disappointed for the students. Just under four-thousand Marshalltown area voters turned out yesterday.