Finding the Fourth Proportional to 2,120.82, 3,181.62 and 659.61

Step by Step Solution

1. Step 1: Write the proportion equation
   2,120.82 : 3,181.62 = 659.61 : x
2. Step 2: Convert to fraction form
   2,120.82/3,181.62 = 659.61/x
3. Step 3: Cross multiply
   2,120.82x = 3,181.62 × 659.61
4. Step 4: Simplify right side
   2,120.82x = 2,098,628.37
5. Step 5: Solve for x
   x = 2,098,628.37/2,120.82
6. Step 6: Final answer
   x = 989.54