Finding the Fourth Proportional to 111,384.10, 166,784.55 and 81,640.90

Step by Step Solution

1. Step 1: Write the proportion equation
   111,384.10 : 166,784.55 = 81,640.90 : x
2. Step 2: Convert to fraction form
   111,384.10/166,784.55 = 81,640.90/x
3. Step 3: Cross multiply
   111,384.10x = 166,784.55 × 81,640.90
4. Step 4: Simplify right side
   111,384.10x = 13,616,440,768.10
5. Step 5: Solve for x
   x = 13,616,440,768.10/111,384.10
6. Step 6: Final answer
   x = 122,247.62