Finding the Fourth Proportional to 2,139.37, 3,208.22 and 658.15

Step by Step Solution

1. Step 1: Write the proportion equation
   2,139.37 : 3,208.22 = 658.15 : x
2. Step 2: Convert to fraction form
   2,139.37/3,208.22 = 658.15/x
3. Step 3: Cross multiply
   2,139.37x = 3,208.22 × 658.15
4. Step 4: Simplify right side
   2,139.37x = 2,111,489.99
5. Step 5: Solve for x
   x = 2,111,489.99/2,139.37
6. Step 6: Final answer
   x = 986.97