Finding the Fourth Proportional to 1,298.70, 1,947.76 and 518.56

Step by Step Solution

1. Step 1: Write the proportion equation
   1,298.70 : 1,947.76 = 518.56 : x
2. Step 2: Convert to fraction form
   1,298.70/1,947.76 = 518.56/x
3. Step 3: Cross multiply
   1,298.70x = 1,947.76 × 518.56
4. Step 4: Simplify right side
   1,298.70x = 1,010,030.43
5. Step 5: Solve for x
   x = 1,010,030.43/1,298.70
6. Step 6: Final answer
   x = 777.72