Finding the Fourth Proportional to 12,721.40, 17,556.56 and 7,057.92

Step by Step Solution

1. Step 1: Write the proportion equation
   12,721.40 : 17,556.56 = 7,057.92 : x
2. Step 2: Convert to fraction form
   12,721.40/17,556.56 = 7,057.92/x
3. Step 3: Cross multiply
   12,721.40x = 17,556.56 × 7,057.92
4. Step 4: Simplify right side
   12,721.40x = 123,912,795.96
5. Step 5: Solve for x
   x = 123,912,795.96/12,721.40
6. Step 6: Final answer
   x = 9,740.50