Finding the Fourth Proportional to 12,821.30, 19,199.55 and 10,229.30

Step by Step Solution

1. Step 1: Write the proportion equation
   12,821.30 : 19,199.55 = 10,229.30 : x
2. Step 2: Convert to fraction form
   12,821.30/19,199.55 = 10,229.30/x
3. Step 3: Cross multiply
   12,821.30x = 19,199.55 × 10,229.30
4. Step 4: Simplify right side
   12,821.30x = 196,397,956.82
5. Step 5: Solve for x
   x = 196,397,956.82/12,821.30
6. Step 6: Final answer
   x = 15,318.10