Finding the Fourth Proportional to 100,665.12, 138,919.52 and 55,345

Step by Step Solution

1. Step 1: Write the proportion equation
   100,665.12 : 138,919.52 = 55,345 : x
2. Step 2: Convert to fraction form
   100,665.12/138,919.52 = 55,345/x
3. Step 3: Cross multiply
   100,665.12x = 138,919.52 × 55,345
4. Step 4: Simplify right side
   100,665.12x = 7,688,500,834.40
5. Step 5: Solve for x
   x = 7,688,500,834.40/100,665.12
6. Step 6: Final answer
   x = 76,377.01