Finding the Fourth Proportional to 22,116.74, 30,491.25 and 21,428.78

Step by Step Solution

1. Step 1: Write the proportion equation
   22,116.74 : 30,491.25 = 21,428.78 : x
2. Step 2: Convert to fraction form
   22,116.74/30,491.25 = 21,428.78/x
3. Step 3: Cross multiply
   22,116.74x = 30,491.25 × 21,428.78
4. Step 4: Simplify right side
   22,116.74x = 653,390,288.18
5. Step 5: Solve for x
   x = 653,390,288.18/22,116.74
6. Step 6: Final answer
   x = 29,542.79