Finding the Fourth Proportional to 1,382.86, 1,907.31 and 939.99

Step by Step Solution

1. Step 1: Write the proportion equation
   1,382.86 : 1,907.31 = 939.99 : x
2. Step 2: Convert to fraction form
   1,382.86/1,907.31 = 939.99/x
3. Step 3: Cross multiply
   1,382.86x = 1,907.31 × 939.99
4. Step 4: Simplify right side
   1,382.86x = 1,792,852.33
5. Step 5: Solve for x
   x = 1,792,852.33/1,382.86
6. Step 6: Final answer
   x = 1,296.48