Finding the Fourth Proportional to 21,912.57, 30,231.02 and 13,407.86

Step by Step Solution

1. Step 1: Write the proportion equation
   21,912.57 : 30,231.02 = 13,407.86 : x
2. Step 2: Convert to fraction form
   21,912.57/30,231.02 = 13,407.86/x
3. Step 3: Cross multiply
   21,912.57x = 30,231.02 × 13,407.86
4. Step 4: Simplify right side
   21,912.57x = 405,333,392.91
5. Step 5: Solve for x
   x = 405,333,392.91/21,912.57
6. Step 6: Final answer
   x = 18,497.76