Housing prices for King County in the month of April were strong, and inventory was down 37 percent from one year ago, reports  the Seattle Times   based on data released by the Northwest Multiple Listing Service. The median house price in King County went up to $360,000, which is 9 percent better than last month and about 3 percent higher than April 2011. Snohomish County’s median house price jumped to $255,502, which is almost 10 percent better than a year ago. A total of 741 homes were sold, 25 percent more than the number closed in April 2011.