Finding the Fourth Proportional to 258,590.34, 387,885.98 and 81,111.11

Step by Step Solution

1. Step 1: Write the proportion equation
   258,590.34 : 387,885.98 = 81,111.11 : x
2. Step 2: Convert to fraction form
   258,590.34/387,885.98 = 81,111.11/x
3. Step 3: Cross multiply
   258,590.34x = 387,885.98 × 81,111.11
4. Step 4: Simplify right side
   258,590.34x = 31,461,860,654.59
5. Step 5: Solve for x
   x = 31,461,860,654.59/258,590.34
6. Step 6: Final answer
   x = 121,666.81