Finding the Fourth Proportional to 12,783.72, 19,085.91 and 10,815.96

Step by Step Solution

1. Step 1: Write the proportion equation
   12,783.72 : 19,085.91 = 10,815.96 : x
2. Step 2: Convert to fraction form
   12,783.72/19,085.91 = 10,815.96/x
3. Step 3: Cross multiply
   12,783.72x = 19,085.91 × 10,815.96
4. Step 4: Simplify right side
   12,783.72x = 206,432,439.12
5. Step 5: Solve for x
   x = 206,432,439.12/12,783.72
6. Step 6: Final answer
   x = 16,148.07