Finding the Fourth Proportional to 2,071.18, 3,107.78 and 839.47

Step by Step Solution

1. Step 1: Write the proportion equation
   2,071.18 : 3,107.78 = 839.47 : x
2. Step 2: Convert to fraction form
   2,071.18/3,107.78 = 839.47/x
3. Step 3: Cross multiply
   2,071.18x = 3,107.78 × 839.47
4. Step 4: Simplify right side
   2,071.18x = 2,608,888.08
5. Step 5: Solve for x
   x = 2,608,888.08/2,071.18
6. Step 6: Final answer
   x = 1,259.61