Finding the Fourth Proportional to 1,083.45, 1,624.69 and 390.09

Step by Step Solution

1. Step 1: Write the proportion equation
   1,083.45 : 1,624.69 = 390.09 : x
2. Step 2: Convert to fraction form
   1,083.45/1,624.69 = 390.09/x
3. Step 3: Cross multiply
   1,083.45x = 1,624.69 × 390.09
4. Step 4: Simplify right side
   1,083.45x = 633,775.32
5. Step 5: Solve for x
   x = 633,775.32/1,083.45
6. Step 6: Final answer
   x = 584.96