Finding the Fourth Proportional to 21,820.86, 30,113.78 and 12,868.74

Step by Step Solution

1. Step 1: Write the proportion equation
   21,820.86 : 30,113.78 = 12,868.74 : x
2. Step 2: Convert to fraction form
   21,820.86/30,113.78 = 12,868.74/x
3. Step 3: Cross multiply
   21,820.86x = 30,113.78 × 12,868.74
4. Step 4: Simplify right side
   21,820.86x = 387,526,340.89
5. Step 5: Solve for x
   x = 387,526,340.89/21,820.86
6. Step 6: Final answer
   x = 17,759.44