Finding the Fourth Proportional to 21,555.25, 29,749.89 and 12,479.29

Step by Step Solution

1. Step 1: Write the proportion equation
   21,555.25 : 29,749.89 = 12,479.29 : x
2. Step 2: Convert to fraction form
   21,555.25/29,749.89 = 12,479.29/x
3. Step 3: Cross multiply
   21,555.25x = 29,749.89 × 12,479.29
4. Step 4: Simplify right side
   21,555.25x = 371,257,504.78
5. Step 5: Solve for x
   x = 371,257,504.78/21,555.25
6. Step 6: Final answer
   x = 17,223.53