Finding the Fourth Proportional to 21,355.02, 31,970.25 and 12,443.14

Step by Step Solution

1. Step 1: Write the proportion equation
   21,355.02 : 31,970.25 = 12,443.14 : x
2. Step 2: Convert to fraction form
   21,355.02/31,970.25 = 12,443.14/x
3. Step 3: Cross multiply
   21,355.02x = 31,970.25 × 12,443.14
4. Step 4: Simplify right side
   21,355.02x = 397,810,296.59
5. Step 5: Solve for x
   x = 397,810,296.59/21,355.02
6. Step 6: Final answer
   x = 18,628.42