Finding the Fourth Proportional to 21,996.42, 30,355.43 and 12,565.05

Step by Step Solution

1. Step 1: Write the proportion equation
   21,996.42 : 30,355.43 = 12,565.05 : x
2. Step 2: Convert to fraction form
   21,996.42/30,355.43 = 12,565.05/x
3. Step 3: Cross multiply
   21,996.42x = 30,355.43 × 12,565.05
4. Step 4: Simplify right side
   21,996.42x = 381,417,495.72
5. Step 5: Solve for x
   x = 381,417,495.72/21,996.42
6. Step 6: Final answer
   x = 17,339.98