Finding the Fourth Proportional to 1,080.72, 1,490.58 and 765.36

Step by Step Solution

1. Step 1: Write the proportion equation
   1,080.72 : 1,490.58 = 765.36 : x
2. Step 2: Convert to fraction form
   1,080.72/1,490.58 = 765.36/x
3. Step 3: Cross multiply
   1,080.72x = 1,490.58 × 765.36
4. Step 4: Simplify right side
   1,080.72x = 1,140,830.31
5. Step 5: Solve for x
   x = 1,140,830.31/1,080.72
6. Step 6: Final answer
   x = 1,055.62