Finding the Fourth Proportional to 8,555.12, 12,845.40 and 5,258.72

Step by Step Solution

1. Step 1: Write the proportion equation
   8,555.12 : 12,845.40 = 5,258.72 : x
2. Step 2: Convert to fraction form
   8,555.12/12,845.40 = 5,258.72/x
3. Step 3: Cross multiply
   8,555.12x = 12,845.40 × 5,258.72
4. Step 4: Simplify right side
   8,555.12x = 67,550,361.89
5. Step 5: Solve for x
   x = 67,550,361.89/8,555.12
6. Step 6: Final answer
   x = 7,895.90