Finding the Fourth Proportional to 2,071.27, 3,105.78 and 665.45

Step by Step Solution

1. Step 1: Write the proportion equation
   2,071.27 : 3,105.78 = 665.45 : x
2. Step 2: Convert to fraction form
   2,071.27/3,105.78 = 665.45/x
3. Step 3: Cross multiply
   2,071.27x = 3,105.78 × 665.45
4. Step 4: Simplify right side
   2,071.27x = 2,066,734.92
5. Step 5: Solve for x
   x = 2,066,734.92/2,071.27
6. Step 6: Final answer
   x = 997.81