Finding the Fourth Proportional to 1,290.82, 1,779.31 and 1,080.62

Step by Step Solution

1. Step 1: Write the proportion equation
   1,290.82 : 1,779.31 = 1,080.62 : x
2. Step 2: Convert to fraction form
   1,290.82/1,779.31 = 1,080.62/x
3. Step 3: Cross multiply
   1,290.82x = 1,779.31 × 1,080.62
4. Step 4: Simplify right side
   1,290.82x = 1,922,757.97
5. Step 5: Solve for x
   x = 1,922,757.97/1,290.82
6. Step 6: Final answer
   x = 1,489.56