Finding the Fourth Proportional to 72,091.90, 99,345.07 and 55,115.31

Step by Step Solution

1. Step 1: Write the proportion equation
   72,091.90 : 99,345.07 = 55,115.31 : x
2. Step 2: Convert to fraction form
   72,091.90/99,345.07 = 55,115.31/x
3. Step 3: Cross multiply
   72,091.90x = 99,345.07 × 55,115.31
4. Step 4: Simplify right side
   72,091.90x = 5,475,434,192.23
5. Step 5: Solve for x
   x = 5,475,434,192.23/72,091.90
6. Step 6: Final answer
   x = 75,950.76