Finding the Fourth Proportional to 3,856.70, 5,392.90 and 3,856.70

Step by Step Solution

1. Step 1: Write the proportion equation
   3,856.70 : 5,392.90 = 3,856.70 : x
2. Step 2: Convert to fraction form
   3,856.70/5,392.90 = 3,856.70/x
3. Step 3: Cross multiply
   3,856.70x = 5,392.90 × 3,856.70
4. Step 4: Simplify right side
   3,856.70x = 20,798,797.43
5. Step 5: Solve for x
   x = 20,798,797.43/3,856.70
6. Step 6: Final answer
   x = 5,392.90