Finding the Fourth Proportional to 20,800.56, 28,704.72 and 12,417.12

Step by Step Solution

1. Step 1: Write the proportion equation
   20,800.56 : 28,704.72 = 12,417.12 : x
2. Step 2: Convert to fraction form
   20,800.56/28,704.72 = 12,417.12/x
3. Step 3: Cross multiply
   20,800.56x = 28,704.72 × 12,417.12
4. Step 4: Simplify right side
   20,800.56x = 356,429,952.81
5. Step 5: Solve for x
   x = 356,429,952.81/20,800.56
6. Step 6: Final answer
   x = 17,135.59