Finding the Fourth Proportional to 2,145.69, 3,218.81 and 758.70

Step by Step Solution

1. Step 1: Write the proportion equation
   2,145.69 : 3,218.81 = 758.70 : x
2. Step 2: Convert to fraction form
   2,145.69/3,218.81 = 758.70/x
3. Step 3: Cross multiply
   2,145.69x = 3,218.81 × 758.70
4. Step 4: Simplify right side
   2,145.69x = 2,442,107.35
5. Step 5: Solve for x
   x = 2,442,107.35/2,145.69
6. Step 6: Final answer
   x = 1,138.15