WESTCHESTER For the second consecutive quarter, residential housing prices in Westchester were unchanged from the same period last year. The mix of property types included single family, multifamily, co-ops and condos. County median sales price was $430,000 in the first quarter, unchanged from the prior year quarter. Average sales price followed the same pattern, remaining essentially unchanged at $621,724 over the same period. Single family home sales represented 58.7% of county-wide residential sales. Like the overall market, single family median sales price was unchanged from the prior year quarter at $600,000. The number of single family sales expanded 4.5% to 967 from the prior year quarter. Listing inventory fell 11.6% over the same period and pending sales are up 3.8%…