Finding the Fourth Proportional to 12,152.91, 16,778.76 and 9,920.10

Step by Step Solution

1. Step 1: Write the proportion equation
   12,152.91 : 16,778.76 = 9,920.10 : x
2. Step 2: Convert to fraction form
   12,152.91/16,778.76 = 9,920.10/x
3. Step 3: Cross multiply
   12,152.91x = 16,778.76 × 9,920.10
4. Step 4: Simplify right side
   12,152.91x = 166,446,875.18
5. Step 5: Solve for x
   x = 166,446,875.18/12,152.91
6. Step 6: Final answer
   x = 13,696.05