Finding the Fourth Proportional to 9,660.40, 13,328.72 and 5,680.08

Step by Step Solution

1. Step 1: Write the proportion equation
   9,660.40 : 13,328.72 = 5,680.08 : x
2. Step 2: Convert to fraction form
   9,660.40/13,328.72 = 5,680.08/x
3. Step 3: Cross multiply
   9,660.40x = 13,328.72 × 5,680.08
4. Step 4: Simplify right side
   9,660.40x = 75,708,195.90
5. Step 5: Solve for x
   x = 75,708,195.90/9,660.40
6. Step 6: Final answer
   x = 7,836.96