Finding the Fourth Proportional to 12,721.98, 17,557.40 and 7,058.55

Step by Step Solution

1. Step 1: Write the proportion equation
   12,721.98 : 17,557.40 = 7,058.55 : x
2. Step 2: Convert to fraction form
   12,721.98/17,557.40 = 7,058.55/x
3. Step 3: Cross multiply
   12,721.98x = 17,557.40 × 7,058.55
4. Step 4: Simplify right side
   12,721.98x = 123,929,803.42
5. Step 5: Solve for x
   x = 123,929,803.42/12,721.98
6. Step 6: Final answer
   x = 9,741.39