Finding the Fourth Proportional to 1,080.33, 1,620.69 and 387.42

Step by Step Solution

1. Step 1: Write the proportion equation
   1,080.33 : 1,620.69 = 387.42 : x
2. Step 2: Convert to fraction form
   1,080.33/1,620.69 = 387.42/x
3. Step 3: Cross multiply
   1,080.33x = 1,620.69 × 387.42
4. Step 4: Simplify right side
   1,080.33x = 627,887.72
5. Step 5: Solve for x
   x = 627,887.72/1,080.33
6. Step 6: Final answer
   x = 581.20