Finding the Fourth Proportional to 2,570.79, 3,856.59 and 839.01

Step by Step Solution

1. Step 1: Write the proportion equation
   2,570.79 : 3,856.59 = 839.01 : x
2. Step 2: Convert to fraction form
   2,570.79/3,856.59 = 839.01/x
3. Step 3: Cross multiply
   2,570.79x = 3,856.59 × 839.01
4. Step 4: Simplify right side
   2,570.79x = 3,235,717.58
5. Step 5: Solve for x
   x = 3,235,717.58/2,570.79
6. Step 6: Final answer
   x = 1,258.65