Finding the Fourth Proportional to 9,579.60, 13,212.72 and 8,458.56

Step by Step Solution

1. Step 1: Write the proportion equation
   9,579.60 : 13,212.72 = 8,458.56 : x
2. Step 2: Convert to fraction form
   9,579.60/13,212.72 = 8,458.56/x
3. Step 3: Cross multiply
   9,579.60x = 13,212.72 × 8,458.56
4. Step 4: Simplify right side
   9,579.60x = 111,760,584.88
5. Step 5: Solve for x
   x = 111,760,584.88/9,579.60
6. Step 6: Final answer
   x = 11,666.52