Finding the Fourth Proportional to 100,985.82, 139,354.10 and 55,661.31

Step by Step Solution

1. Step 1: Write the proportion equation
   100,985.82 : 139,354.10 = 55,661.31 : x
2. Step 2: Convert to fraction form
   100,985.82/139,354.10 = 55,661.31/x
3. Step 3: Cross multiply
   100,985.82x = 139,354.10 × 55,661.31
4. Step 4: Simplify right side
   100,985.82x = 7,756,631,725.33
5. Step 5: Solve for x
   x = 7,756,631,725.33/100,985.82
6. Step 6: Final answer
   x = 76,809.11