Finding the Fourth Proportional to 21,780.38, 30,062.39 and 12,824.61

Step by Step Solution

1. Step 1: Write the proportion equation
   21,780.38 : 30,062.39 = 12,824.61 : x
2. Step 2: Convert to fraction form
   21,780.38/30,062.39 = 12,824.61/x
3. Step 3: Cross multiply
   21,780.38x = 30,062.39 × 12,824.61
4. Step 4: Simplify right side
   21,780.38x = 385,538,427.42
5. Step 5: Solve for x
   x = 385,538,427.42/21,780.38
6. Step 6: Final answer
   x = 17,701.18