Church & Dwight Co. on Tuesday posted a nearly 12 percent increase in its third-quarter profit, helped by higher selling prices and acquisitions. The Princeton-based consumer-products company—which makes Arm & Hammer baking soda and Brillo soap pads, among other goods—said its net income rose to $38.7 million, or 57 cents a share, in the three months ended Sept. 29. That’s up from $34.6 million, or 51 cents a share, in the prior third quarter. Sales increased 17 percent to $5...