Finding the Fourth Proportional to 21,255.42, 31,848.09 and 12,345.74

Step by Step Solution

1. Step 1: Write the proportion equation
   21,255.42 : 31,848.09 = 12,345.74 : x
2. Step 2: Convert to fraction form
   21,255.42/31,848.09 = 12,345.74/x
3. Step 3: Cross multiply
   21,255.42x = 31,848.09 × 12,345.74
4. Step 4: Simplify right side
   21,255.42x = 393,188,155.55
5. Step 5: Solve for x
   x = 393,188,155.55/21,255.42
6. Step 6: Final answer
   x = 18,498.26