Finding the Fourth Proportional to 1,296.78, 1,944.45 and 516.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,296.78 : 1,944.45 = 516.72 : x
2. Step 2: Convert to fraction form
   1,296.78/1,944.45 = 516.72/x
3. Step 3: Cross multiply
   1,296.78x = 1,944.45 × 516.72
4. Step 4: Simplify right side
   1,296.78x = 1,004,736.20
5. Step 5: Solve for x
   x = 1,004,736.20/1,296.78
6. Step 6: Final answer
   x = 774.79