Finding the Fourth Proportional to 258,890.72, 388,326.86 and 90,410.38

Step by Step Solution

1. Step 1: Write the proportion equation
   258,890.72 : 388,326.86 = 90,410.38 : x
2. Step 2: Convert to fraction form
   258,890.72/388,326.86 = 90,410.38/x
3. Step 3: Cross multiply
   258,890.72x = 388,326.86 × 90,410.38
4. Step 4: Simplify right side
   258,890.72x = 35,108,777,892.98
5. Step 5: Solve for x
   x = 35,108,777,892.98/258,890.72
6. Step 6: Final answer
   x = 135,612.35