First we need to find the cost per square foot for the first rug:
Total square feet of first rug = 10 ft x 11 ft = 110 square feet.
Divide total price by total square feet to get the price per square foot:
$348.00 / 110 = $3.164 per square foot
The total square feet of the larger rug:
15 x 16 = 240 square feet
Multiply the total square feet by price per square feet:
240 * $3.164 = $759.36
Depending on how the cost per square foot is rounded the new price may vary a little bit.