Finding the Fourth Proportional to 11,687.92, 16,128.69 and 7,211.99

Step by Step Solution

1. Step 1: Write the proportion equation
   11,687.92 : 16,128.69 = 7,211.99 : x
2. Step 2: Convert to fraction form
   11,687.92/16,128.69 = 7,211.99/x
3. Step 3: Cross multiply
   11,687.92x = 16,128.69 × 7,211.99
4. Step 4: Simplify right side
   11,687.92x = 116,319,964.27
5. Step 5: Solve for x
   x = 116,319,964.27/11,687.92
6. Step 6: Final answer
   x = 9,952.15