Finding the Fourth Proportional to 8,991.20, 12,405.72 and 5,454.32

Step by Step Solution

1. Step 1: Write the proportion equation
   8,991.20 : 12,405.72 = 5,454.32 : x
2. Step 2: Convert to fraction form
   8,991.20/12,405.72 = 5,454.32/x
3. Step 3: Cross multiply
   8,991.20x = 12,405.72 × 5,454.32
4. Step 4: Simplify right side
   8,991.20x = 67,664,766.71
5. Step 5: Solve for x
   x = 67,664,766.71/8,991.20
6. Step 6: Final answer
   x = 7,525.67