Finding the Fourth Proportional to 2,071.75, 3,107.60 and 839.15

Step by Step Solution

1. Step 1: Write the proportion equation
   2,071.75 : 3,107.60 = 839.15 : x
2. Step 2: Convert to fraction form
   2,071.75/3,107.60 = 839.15/x
3. Step 3: Cross multiply
   2,071.75x = 3,107.60 × 839.15
4. Step 4: Simplify right side
   2,071.75x = 2,607,742.54
5. Step 5: Solve for x
   x = 2,607,742.54/2,071.75
6. Step 6: Final answer
   x = 1,258.71