Finding the Fourth Proportional to 21,787.86, 30,065.49 and 12,357.30

Step by Step Solution

1. Step 1: Write the proportion equation
   21,787.86 : 30,065.49 = 12,357.30 : x
2. Step 2: Convert to fraction form
   21,787.86/30,065.49 = 12,357.30/x
3. Step 3: Cross multiply
   21,787.86x = 30,065.49 × 12,357.30
4. Step 4: Simplify right side
   21,787.86x = 371,528,279.58
5. Step 5: Solve for x
   x = 371,528,279.58/21,787.86
6. Step 6: Final answer
   x = 17,052.08