Finding the Fourth Proportional to 111,838.69, 154,312.05 and 81,640.45

Step by Step Solution

1. Step 1: Write the proportion equation
   111,838.69 : 154,312.05 = 81,640.45 : x
2. Step 2: Convert to fraction form
   111,838.69/154,312.05 = 81,640.45/x
3. Step 3: Cross multiply
   111,838.69x = 154,312.05 × 81,640.45
4. Step 4: Simplify right side
   111,838.69x = 12,598,105,202.42
5. Step 5: Solve for x
   x = 12,598,105,202.42/111,838.69
6. Step 6: Final answer
   x = 112,645.32