Finding the Fourth Proportional to 21,818.18, 30,112.98 and 12,865.16

Step by Step Solution

1. Step 1: Write the proportion equation
   21,818.18 : 30,112.98 = 12,865.16 : x
2. Step 2: Convert to fraction form
   21,818.18/30,112.98 = 12,865.16/x
3. Step 3: Cross multiply
   21,818.18x = 30,112.98 × 12,865.16
4. Step 4: Simplify right side
   21,818.18x = 387,408,305.78
5. Step 5: Solve for x
   x = 387,408,305.78/21,818.18
6. Step 6: Final answer
   x = 17,756.22