Finding the Fourth Proportional to 2,571.09, 3,856.58 and 839.71

Step by Step Solution

1. Step 1: Write the proportion equation
   2,571.09 : 3,856.58 = 839.71 : x
2. Step 2: Convert to fraction form
   2,571.09/3,856.58 = 839.71/x
3. Step 3: Cross multiply
   2,571.09x = 3,856.58 × 839.71
4. Step 4: Simplify right side
   2,571.09x = 3,238,412.56
5. Step 5: Solve for x
   x = 3,238,412.56/2,571.09
6. Step 6: Final answer
   x = 1,259.55