Finding the Fourth Proportional to 8,228.78, 12,323.55 and 5,257.89

Step by Step Solution

1. Step 1: Write the proportion equation
   8,228.78 : 12,323.55 = 5,257.89 : x
2. Step 2: Convert to fraction form
   8,228.78/12,323.55 = 5,257.89/x
3. Step 3: Cross multiply
   8,228.78x = 12,323.55 × 5,257.89
4. Step 4: Simplify right side
   8,228.78x = 64,795,870.31
5. Step 5: Solve for x
   x = 64,795,870.31/8,228.78
6. Step 6: Final answer
   x = 7,874.30