Finding the Fourth Proportional to 2,143.35, 3,215.51 and 756.78

Step by Step Solution

1. Step 1: Write the proportion equation
   2,143.35 : 3,215.51 = 756.78 : x
2. Step 2: Convert to fraction form
   2,143.35/3,215.51 = 756.78/x
3. Step 3: Cross multiply
   2,143.35x = 3,215.51 × 756.78
4. Step 4: Simplify right side
   2,143.35x = 2,433,429.87
5. Step 5: Solve for x
   x = 2,433,429.87/2,143.35
6. Step 6: Final answer
   x = 1,135.34