Finding the Fourth Proportional to 5,215.31, 7,197.30 and 2,857.61

Step by Step Solution

1. Step 1: Write the proportion equation
   5,215.31 : 7,197.30 = 2,857.61 : x
2. Step 2: Convert to fraction form
   5,215.31/7,197.30 = 2,857.61/x
3. Step 3: Cross multiply
   5,215.31x = 7,197.30 × 2,857.61
4. Step 4: Simplify right side
   5,215.31x = 20,567,040.47
5. Step 5: Solve for x
   x = 20,567,040.47/5,215.31
6. Step 6: Final answer
   x = 3,943.59