Finding the Fourth Proportional to 89,644.28, 123,442.28 and 87,655.20

Step by Step Solution

1. Step 1: Write the proportion equation
   89,644.28 : 123,442.28 = 87,655.20 : x
2. Step 2: Convert to fraction form
   89,644.28/123,442.28 = 87,655.20/x
3. Step 3: Cross multiply
   89,644.28x = 123,442.28 × 87,655.20
4. Step 4: Simplify right side
   89,644.28x = 10,820,357,741.86
5. Step 5: Solve for x
   x = 10,820,357,741.86/89,644.28
6. Step 6: Final answer
   x = 120,703.27