Finding the Fourth Proportional to 12,721.83, 17,555.16 and 7,131.75

Step by Step Solution

1. Step 1: Write the proportion equation
   12,721.83 : 17,555.16 = 7,131.75 : x
2. Step 2: Convert to fraction form
   12,721.83/17,555.16 = 7,131.75/x
3. Step 3: Cross multiply
   12,721.83x = 17,555.16 × 7,131.75
4. Step 4: Simplify right side
   12,721.83x = 125,199,012.33
5. Step 5: Solve for x
   x = 125,199,012.33/12,721.83
6. Step 6: Final answer
   x = 9,841.27