Finding the Fourth Proportional to 8,443.90, 12,629.40 and 7,131.70

Step by Step Solution

1. Step 1: Write the proportion equation
   8,443.90 : 12,629.40 = 7,131.70 : x
2. Step 2: Convert to fraction form
   8,443.90/12,629.40 = 7,131.70/x
3. Step 3: Cross multiply
   8,443.90x = 12,629.40 × 7,131.70
4. Step 4: Simplify right side
   8,443.90x = 90,069,091.98
5. Step 5: Solve for x
   x = 90,069,091.98/8,443.90
6. Step 6: Final answer
   x = 10,666.76