Finding the Fourth Proportional to 1,399.74, 1,930.77 and 1,007.28

Step by Step Solution

1. Step 1: Write the proportion equation
   1,399.74 : 1,930.77 = 1,007.28 : x
2. Step 2: Convert to fraction form
   1,399.74/1,930.77 = 1,007.28/x
3. Step 3: Cross multiply
   1,399.74x = 1,930.77 × 1,007.28
4. Step 4: Simplify right side
   1,399.74x = 1,944,826.01
5. Step 5: Solve for x
   x = 1,944,826.01/1,399.74
6. Step 6: Final answer
   x = 1,389.42