Finding the Fourth Proportional to 9,659.56, 13,330.20 and 5,680.72

Step by Step Solution

1. Step 1: Write the proportion equation
   9,659.56 : 13,330.20 = 5,680.72 : x
2. Step 2: Convert to fraction form
   9,659.56/13,330.20 = 5,680.72/x
3. Step 3: Cross multiply
   9,659.56x = 13,330.20 × 5,680.72
4. Step 4: Simplify right side
   9,659.56x = 75,725,133.74
5. Step 5: Solve for x
   x = 75,725,133.74/9,659.56
6. Step 6: Final answer
   x = 7,839.40