Finding the Fourth Proportional to 1,080.98, 1,491.38 and 608.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,080.98 : 1,491.38 = 608.78 : x
2. Step 2: Convert to fraction form
   1,080.98/1,491.38 = 608.78/x
3. Step 3: Cross multiply
   1,080.98x = 1,491.38 × 608.78
4. Step 4: Simplify right side
   1,080.98x = 907,922.32
5. Step 5: Solve for x
   x = 907,922.32/1,080.98
6. Step 6: Final answer
   x = 839.91