Finding the Fourth Proportional to 80,661.28, 120,978.24 and 21,503.20

Step by Step Solution

1. Step 1: Write the proportion equation
   80,661.28 : 120,978.24 = 21,503.20 : x
2. Step 2: Convert to fraction form
   80,661.28/120,978.24 = 21,503.20/x
3. Step 3: Cross multiply
   80,661.28x = 120,978.24 × 21,503.20
4. Step 4: Simplify right side
   80,661.28x = 2,601,419,290.37
5. Step 5: Solve for x
   x = 2,601,419,290.37/80,661.28
6. Step 6: Final answer
   x = 32,251.15