Finding the Fourth Proportional to 5,215.89, 7,198.17 and 2,857.98

Step by Step Solution

1. Step 1: Write the proportion equation
   5,215.89 : 7,198.17 = 2,857.98 : x
2. Step 2: Convert to fraction form
   5,215.89/7,198.17 = 2,857.98/x
3. Step 3: Cross multiply
   5,215.89x = 7,198.17 × 2,857.98
4. Step 4: Simplify right side
   5,215.89x = 20,572,225.90
5. Step 5: Solve for x
   x = 20,572,225.90/5,215.89
6. Step 6: Final answer
   x = 3,944.14