Finding the Fourth Proportional to 1,389.10, 1,916.88 and 759.61

Step by Step Solution

1. Step 1: Write the proportion equation
   1,389.10 : 1,916.88 = 759.61 : x
2. Step 2: Convert to fraction form
   1,389.10/1,916.88 = 759.61/x
3. Step 3: Cross multiply
   1,389.10x = 1,916.88 × 759.61
4. Step 4: Simplify right side
   1,389.10x = 1,456,081.22
5. Step 5: Solve for x
   x = 1,456,081.22/1,389.10
6. Step 6: Final answer
   x = 1,048.22