Finding the Fourth Proportional to 21,165.30, 31,683.15 and 12,374.10

Step by Step Solution

1. Step 1: Write the proportion equation
   21,165.30 : 31,683.15 = 12,374.10 : x
2. Step 2: Convert to fraction form
   21,165.30/31,683.15 = 12,374.10/x
3. Step 3: Cross multiply
   21,165.30x = 31,683.15 × 12,374.10
4. Step 4: Simplify right side
   21,165.30x = 392,050,466.42
5. Step 5: Solve for x
   x = 392,050,466.42/21,165.30
6. Step 6: Final answer
   x = 18,523.27