Finding the Fourth Proportional to 21,805.14, 30,086.98 and 12,855.45

Step by Step Solution

1. Step 1: Write the proportion equation
   21,805.14 : 30,086.98 = 12,855.45 : x
2. Step 2: Convert to fraction form
   21,805.14/30,086.98 = 12,855.45/x
3. Step 3: Cross multiply
   21,805.14x = 30,086.98 × 12,855.45
4. Step 4: Simplify right side
   21,805.14x = 386,781,667.04
5. Step 5: Solve for x
   x = 386,781,667.04/21,805.14
6. Step 6: Final answer
   x = 17,738.10