Finding the Fourth Proportional to 1,081.58, 1,621.96 and 388.06

Step by Step Solution

1. Step 1: Write the proportion equation
   1,081.58 : 1,621.96 = 388.06 : x
2. Step 2: Convert to fraction form
   1,081.58/1,621.96 = 388.06/x
3. Step 3: Cross multiply
   1,081.58x = 1,621.96 × 388.06
4. Step 4: Simplify right side
   1,081.58x = 629,407.75
5. Step 5: Solve for x
   x = 629,407.75/1,081.58
6. Step 6: Final answer
   x = 581.94