Finding the Fourth Proportional to 2,080.10, 3,121.74 and 765.10

Step by Step Solution

1. Step 1: Write the proportion equation
   2,080.10 : 3,121.74 = 765.10 : x
2. Step 2: Convert to fraction form
   2,080.10/3,121.74 = 765.10/x
3. Step 3: Cross multiply
   2,080.10x = 3,121.74 × 765.10
4. Step 4: Simplify right side
   2,080.10x = 2,388,443.27
5. Step 5: Solve for x
   x = 2,388,443.27/2,080.10
6. Step 6: Final answer
   x = 1,148.23