Finding the Fourth Proportional to 1,399.06, 1,930.77 and 839.56

Step by Step Solution

1. Step 1: Write the proportion equation
   1,399.06 : 1,930.77 = 839.56 : x
2. Step 2: Convert to fraction form
   1,399.06/1,930.77 = 839.56/x
3. Step 3: Cross multiply
   1,399.06x = 1,930.77 × 839.56
4. Step 4: Simplify right side
   1,399.06x = 1,620,997.26
5. Step 5: Solve for x
   x = 1,620,997.26/1,399.06
6. Step 6: Final answer
   x = 1,158.63