Finding the Fourth Proportional to 12,780.72, 19,146.47 and 10,443.35

Step by Step Solution

1. Step 1: Write the proportion equation
   12,780.72 : 19,146.47 = 10,443.35 : x
2. Step 2: Convert to fraction form
   12,780.72/19,146.47 = 10,443.35/x
3. Step 3: Cross multiply
   12,780.72x = 19,146.47 × 10,443.35
4. Step 4: Simplify right side
   12,780.72x = 199,953,283.12
5. Step 5: Solve for x
   x = 199,953,283.12/12,780.72
6. Step 6: Final answer
   x = 15,644.92