Finding the Fourth Proportional to 6,787.18, 10,165.72 and 5,215.61

Step by Step Solution

1. Step 1: Write the proportion equation
   6,787.18 : 10,165.72 = 5,215.61 : x
2. Step 2: Convert to fraction form
   6,787.18/10,165.72 = 5,215.61/x
3. Step 3: Cross multiply
   6,787.18x = 10,165.72 × 5,215.61
4. Step 4: Simplify right side
   6,787.18x = 53,020,430.89
5. Step 5: Solve for x
   x = 53,020,430.89/6,787.18
6. Step 6: Final answer
   x = 7,811.85