Sales at U.S. wholesalers bounced back in April after tepid sales in the previous three months, the Commerce Department reported Wednesday. Sales rose 1.5% in April, the biggest gain in 13 months. Meanwhile, inventories increased 0.8%. The inventory-to-sales ratio fell to 1.18 from 1.19. The record low was 1.14 in April 2004. Economists were expecting inventories to rise about 0.5% in April, according to a survey conducted by MarketWatch. Financial markets rarely react to the wholesale trade data. They are chiefly of interest to economists, who use the data to fill in gaps in their estimates of gross domestic product.