Finding the Fourth Proportional to 72,390.89, 108,807.75 and 70,840.55

Step by Step Solution

1. Step 1: Write the proportion equation
   72,390.89 : 108,807.75 = 70,840.55 : x
2. Step 2: Convert to fraction form
   72,390.89/108,807.75 = 70,840.55/x
3. Step 3: Cross multiply
   72,390.89x = 108,807.75 × 70,840.55
4. Step 4: Simplify right side
   72,390.89x = 7,708,000,310.22
5. Step 5: Solve for x
   x = 7,708,000,310.22/72,390.89
6. Step 6: Final answer
   x = 106,477.50