Finding the Fourth Proportional to 21,825.38, 30,117.60 and 12,870.83

Step by Step Solution

1. Step 1: Write the proportion equation
   21,825.38 : 30,117.60 = 12,870.83 : x
2. Step 2: Convert to fraction form
   21,825.38/30,117.60 = 12,870.83/x
3. Step 3: Cross multiply
   21,825.38x = 30,117.60 × 12,870.83
4. Step 4: Simplify right side
   21,825.38x = 387,638,359.02
5. Step 5: Solve for x
   x = 387,638,359.02/21,825.38
6. Step 6: Final answer
   x = 17,760.90