Finding the Fourth Proportional to 2,570.76, 3,856.70 and 839.56

Step by Step Solution

1. Step 1: Write the proportion equation
   2,570.76 : 3,856.70 = 839.56 : x
2. Step 2: Convert to fraction form
   2,570.76/3,856.70 = 839.56/x
3. Step 3: Cross multiply
   2,570.76x = 3,856.70 × 839.56
4. Step 4: Simplify right side
   2,570.76x = 3,237,931.05
5. Step 5: Solve for x
   x = 3,237,931.05/2,570.76
6. Step 6: Final answer
   x = 1,259.52