Finding the Fourth Proportional to 2,571.39, 3,856.68 and 928.71

Step by Step Solution

1. Step 1: Write the proportion equation
   2,571.39 : 3,856.68 = 928.71 : x
2. Step 2: Convert to fraction form
   2,571.39/3,856.68 = 928.71/x
3. Step 3: Cross multiply
   2,571.39x = 3,856.68 × 928.71
4. Step 4: Simplify right side
   2,571.39x = 3,581,737.28
5. Step 5: Solve for x
   x = 3,581,737.28/2,571.39
6. Step 6: Final answer
   x = 1,392.92