Finding the Fourth Proportional to 21,781.91, 30,059.40 and 12,223.91

Step by Step Solution

1. Step 1: Write the proportion equation
   21,781.91 : 30,059.40 = 12,223.91 : x
2. Step 2: Convert to fraction form
   21,781.91/30,059.40 = 12,223.91/x
3. Step 3: Cross multiply
   21,781.91x = 30,059.40 × 12,223.91
4. Step 4: Simplify right side
   21,781.91x = 367,443,521.24
5. Step 5: Solve for x
   x = 367,443,521.24/21,781.91
6. Step 6: Final answer
   x = 16,869.20