Finding the Fourth Proportional to 1,080.30, 1,490.78 and 608.18

Step by Step Solution

1. Step 1: Write the proportion equation
   1,080.30 : 1,490.78 = 608.18 : x
2. Step 2: Convert to fraction form
   1,080.30/1,490.78 = 608.18/x
3. Step 3: Cross multiply
   1,080.30x = 1,490.78 × 608.18
4. Step 4: Simplify right side
   1,080.30x = 906,662.58
5. Step 5: Solve for x
   x = 906,662.58/1,080.30
6. Step 6: Final answer
   x = 839.27