Finding the Fourth Proportional to 1,083.98, 1,626.62 and 390.59

Step by Step Solution

1. Step 1: Write the proportion equation
   1,083.98 : 1,626.62 = 390.59 : x
2. Step 2: Convert to fraction form
   1,083.98/1,626.62 = 390.59/x
3. Step 3: Cross multiply
   1,083.98x = 1,626.62 × 390.59
4. Step 4: Simplify right side
   1,083.98x = 635,341.51
5. Step 5: Solve for x
   x = 635,341.51/1,083.98
6. Step 6: Final answer
   x = 586.12