Finding the Fourth Proportional to 9,105.12, 12,553.92 and 7,212.96

Step by Step Solution

1. Step 1: Write the proportion equation
   9,105.12 : 12,553.92 = 7,212.96 : x
2. Step 2: Convert to fraction form
   9,105.12/12,553.92 = 7,212.96/x
3. Step 3: Cross multiply
   9,105.12x = 12,553.92 × 7,212.96
4. Step 4: Simplify right side
   9,105.12x = 90,550,922.80
5. Step 5: Solve for x
   x = 90,550,922.80/9,105.12
6. Step 6: Final answer
   x = 9,945.06