Finding the Fourth Proportional to 8,891.40, 12,270.78 and 5,356.56

Step by Step Solution

1. Step 1: Write the proportion equation
   8,891.40 : 12,270.78 = 5,356.56 : x
2. Step 2: Convert to fraction form
   8,891.40/12,270.78 = 5,356.56/x
3. Step 3: Cross multiply
   8,891.40x = 12,270.78 × 5,356.56
4. Step 4: Simplify right side
   8,891.40x = 65,729,169.32
5. Step 5: Solve for x
   x = 65,729,169.32/8,891.40
6. Step 6: Final answer
   x = 7,392.44