Finding the Fourth Proportional to 1,007.38, 1,390.17 and 559.25

Step by Step Solution

1. Step 1: Write the proportion equation
   1,007.38 : 1,390.17 = 559.25 : x
2. Step 2: Convert to fraction form
   1,007.38/1,390.17 = 559.25/x
3. Step 3: Cross multiply
   1,007.38x = 1,390.17 × 559.25
4. Step 4: Simplify right side
   1,007.38x = 777,456.84
5. Step 5: Solve for x
   x = 777,456.84/1,007.38
6. Step 6: Final answer
   x = 771.76