Finding the Fourth Proportional to 1,290.24, 1,780.38 and 758.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,290.24 : 1,780.38 = 758.72 : x
2. Step 2: Convert to fraction form
   1,290.24/1,780.38 = 758.72/x
3. Step 3: Cross multiply
   1,290.24x = 1,780.38 × 758.72
4. Step 4: Simplify right side
   1,290.24x = 1,350,809.91
5. Step 5: Solve for x
   x = 1,350,809.91/1,290.24
6. Step 6: Final answer
   x = 1,046.94