Finding the Fourth Proportional to 7,018.10, 9,685.81 and 5,128.73

Step by Step Solution

1. Step 1: Write the proportion equation
   7,018.10 : 9,685.81 = 5,128.73 : x
2. Step 2: Convert to fraction form
   7,018.10/9,685.81 = 5,128.73/x
3. Step 3: Cross multiply
   7,018.10x = 9,685.81 × 5,128.73
4. Step 4: Simplify right side
   7,018.10x = 49,675,904.32
5. Step 5: Solve for x
   x = 49,675,904.32/7,018.10
6. Step 6: Final answer
   x = 7,078.26