Finding the Fourth Proportional to 8,957.76, 12,361.60 and 4,978.72

Step by Step Solution

1. Step 1: Write the proportion equation
   8,957.76 : 12,361.60 = 4,978.72 : x
2. Step 2: Convert to fraction form
   8,957.76/12,361.60 = 4,978.72/x
3. Step 3: Cross multiply
   8,957.76x = 12,361.60 × 4,978.72
4. Step 4: Simplify right side
   8,957.76x = 61,544,945.15
5. Step 5: Solve for x
   x = 61,544,945.15/8,957.76
6. Step 6: Final answer
   x = 6,870.57