Finding the Fourth Proportional to 8,790.64, 12,139.67 and 7,524.47

Step by Step Solution

1. Step 1: Write the proportion equation
   8,790.64 : 12,139.67 = 7,524.47 : x
2. Step 2: Convert to fraction form
   8,790.64/12,139.67 = 7,524.47/x
3. Step 3: Cross multiply
   8,790.64x = 12,139.67 × 7,524.47
4. Step 4: Simplify right side
   8,790.64x = 91,344,582.72
5. Step 5: Solve for x
   x = 91,344,582.72/8,790.64
6. Step 6: Final answer
   x = 10,391.12