Finding the Fourth Proportional to 22,890.21, 31,587.62 and 12,818.15

Step by Step Solution

1. Step 1: Write the proportion equation
   22,890.21 : 31,587.62 = 12,818.15 : x
2. Step 2: Convert to fraction form
   22,890.21/31,587.62 = 12,818.15/x
3. Step 3: Cross multiply
   22,890.21x = 31,587.62 × 12,818.15
4. Step 4: Simplify right side
   22,890.21x = 404,894,851.30
5. Step 5: Solve for x
   x = 404,894,851.30/22,890.21
6. Step 6: Final answer
   x = 17,688.56