Finding the Fourth Proportional to 8,891.40, 12,270.06 and 4,912.78

Step by Step Solution

1. Step 1: Write the proportion equation
   8,891.40 : 12,270.06 = 4,912.78 : x
2. Step 2: Convert to fraction form
   8,891.40/12,270.06 = 4,912.78/x
3. Step 3: Cross multiply
   8,891.40x = 12,270.06 × 4,912.78
4. Step 4: Simplify right side
   8,891.40x = 60,280,105.37
5. Step 5: Solve for x
   x = 60,280,105.37/8,891.40
6. Step 6: Final answer
   x = 6,779.60