Finding the Fourth Proportional to 12,761.28, 17,610.72 and 7,172.16

Step by Step Solution

1. Step 1: Write the proportion equation
   12,761.28 : 17,610.72 = 7,172.16 : x
2. Step 2: Convert to fraction form
   12,761.28/17,610.72 = 7,172.16/x
3. Step 3: Cross multiply
   12,761.28x = 17,610.72 × 7,172.16
4. Step 4: Simplify right side
   12,761.28x = 126,306,901.56
5. Step 5: Solve for x
   x = 126,306,901.56/12,761.28
6. Step 6: Final answer
   x = 9,897.67