Finding the Fourth Proportional to 1,086.65, 1,630.38 and 393.29

Step by Step Solution

1. Step 1: Write the proportion equation
   1,086.65 : 1,630.38 = 393.29 : x
2. Step 2: Convert to fraction form
   1,086.65/1,630.38 = 393.29/x
3. Step 3: Cross multiply
   1,086.65x = 1,630.38 × 393.29
4. Step 4: Simplify right side
   1,086.65x = 641,212.15
5. Step 5: Solve for x
   x = 641,212.15/1,086.65
6. Step 6: Final answer
   x = 590.08