Finding the Fourth Proportional to 90,469.23, 135,915.89 and 85,356.83

Step by Step Solution

1. Step 1: Write the proportion equation
   90,469.23 : 135,915.89 = 85,356.83 : x
2. Step 2: Convert to fraction form
   90,469.23/135,915.89 = 85,356.83/x
3. Step 3: Cross multiply
   90,469.23x = 135,915.89 × 85,356.83
4. Step 4: Simplify right side
   90,469.23x = 11,601,349,517.03
5. Step 5: Solve for x
   x = 11,601,349,517.03/90,469.23
6. Step 6: Final answer
   x = 128,235.31