U.S. business inventories jumped 1.2% in November, the government said Friday. Sales rose 0.7% in the month. An increase in inventories adds to gross domestic product and is usually a sign of an expanding economy. The ratio of inventories to sales, meanwhile, rose to 1.25 from 1.24. That’s how many months it would take to sell all the inventory on hand. Inventories soared early in the pandemic as sales slumped, but now companies can’t keep enough inventory in stock. Sales are strong, but shortages of supplies and labor are holding back production.