Finding the Fourth Proportional to 9,639.12, 13,306.31 and 5,660.47

Step by Step Solution

1. Step 1: Write the proportion equation
   9,639.12 : 13,306.31 = 5,660.47 : x
2. Step 2: Convert to fraction form
   9,639.12/13,306.31 = 5,660.47/x
3. Step 3: Cross multiply
   9,639.12x = 13,306.31 × 5,660.47
4. Step 4: Simplify right side
   9,639.12x = 75,319,968.57
5. Step 5: Solve for x
   x = 75,319,968.57/9,639.12
6. Step 6: Final answer
   x = 7,813.99