Finding the Fourth Proportional to 2,057.71, 3,086.85 and 670.78

Step by Step Solution

1. Step 1: Write the proportion equation
   2,057.71 : 3,086.85 = 670.78 : x
2. Step 2: Convert to fraction form
   2,057.71/3,086.85 = 670.78/x
3. Step 3: Cross multiply
   2,057.71x = 3,086.85 × 670.78
4. Step 4: Simplify right side
   2,057.71x = 2,070,597.24
5. Step 5: Solve for x
   x = 2,070,597.24/2,057.71
6. Step 6: Final answer
   x = 1,006.26