Finding the Fourth Proportional to 8,561.56, 12,780.38 and 7,399.02

Step by Step Solution

1. Step 1: Write the proportion equation
   8,561.56 : 12,780.38 = 7,399.02 : x
2. Step 2: Convert to fraction form
   8,561.56/12,780.38 = 7,399.02/x
3. Step 3: Cross multiply
   8,561.56x = 12,780.38 × 7,399.02
4. Step 4: Simplify right side
   8,561.56x = 94,562,287.23
5. Step 5: Solve for x
   x = 94,562,287.23/8,561.56
6. Step 6: Final answer
   x = 11,044.98