Finding the Fourth Proportional to 9,861.28, 13,607.10 and 5,668.72

Step by Step Solution

1. Step 1: Write the proportion equation
   9,861.28 : 13,607.10 = 5,668.72 : x
2. Step 2: Convert to fraction form
   9,861.28/13,607.10 = 5,668.72/x
3. Step 3: Cross multiply
   9,861.28x = 13,607.10 × 5,668.72
4. Step 4: Simplify right side
   9,861.28x = 77,134,839.91
5. Step 5: Solve for x
   x = 77,134,839.91/9,861.28
6. Step 6: Final answer
   x = 7,821.99