Finding the Fourth Proportional to 39,901.20, 55,061.28 and 21,996.96

Step by Step Solution

1. Step 1: Write the proportion equation
   39,901.20 : 55,061.28 = 21,996.96 : x
2. Step 2: Convert to fraction form
   39,901.20/55,061.28 = 21,996.96/x
3. Step 3: Cross multiply
   39,901.20x = 55,061.28 × 21,996.96
4. Step 4: Simplify right side
   39,901.20x = 1,211,180,773.71
5. Step 5: Solve for x
   x = 1,211,180,773.71/39,901.20
6. Step 6: Final answer
   x = 30,354.49