Finding the Fourth Proportional to 1,389.35, 1,917.20 and 759.85

Step by Step Solution

1. Step 1: Write the proportion equation
   1,389.35 : 1,917.20 = 759.85 : x
2. Step 2: Convert to fraction form
   1,389.35/1,917.20 = 759.85/x
3. Step 3: Cross multiply
   1,389.35x = 1,917.20 × 759.85
4. Step 4: Simplify right side
   1,389.35x = 1,456,781.53
5. Step 5: Solve for x
   x = 1,456,781.53/1,389.35
6. Step 6: Final answer
   x = 1,048.53