Finding the Fourth Proportional to 9,009.60, 12,474.72 and 8,779.20

Step by Step Solution

1. Step 1: Write the proportion equation
   9,009.60 : 12,474.72 = 8,779.20 : x
2. Step 2: Convert to fraction form
   9,009.60/12,474.72 = 8,779.20/x
3. Step 3: Cross multiply
   9,009.60x = 12,474.72 × 8,779.20
4. Step 4: Simplify right side
   9,009.60x = 109,518,061.82
5. Step 5: Solve for x
   x = 109,518,061.82/9,009.60
6. Step 6: Final answer
   x = 12,155.71