Finding the Fourth Proportional to 256,499.86, 384,730.35 and 90,171.22

Step by Step Solution

1. Step 1: Write the proportion equation
   256,499.86 : 384,730.35 = 90,171.22 : x
2. Step 2: Convert to fraction form
   256,499.86/384,730.35 = 90,171.22/x
3. Step 3: Cross multiply
   256,499.86x = 384,730.35 × 90,171.22
4. Step 4: Simplify right side
   256,499.86x = 34,691,605,030.53
5. Step 5: Solve for x
   x = 34,691,605,030.53/256,499.86
6. Step 6: Final answer
   x = 135,250.00