Finding the Fourth Proportional to 2,398.77, 3,599.20 and 839.89

Step by Step Solution

1. Step 1: Write the proportion equation
   2,398.77 : 3,599.20 = 839.89 : x
2. Step 2: Convert to fraction form
   2,398.77/3,599.20 = 839.89/x
3. Step 3: Cross multiply
   2,398.77x = 3,599.20 × 839.89
4. Step 4: Simplify right side
   2,398.77x = 3,022,914.09
5. Step 5: Solve for x
   x = 3,022,914.09/2,398.77
6. Step 6: Final answer
   x = 1,260.20