Finding the Fourth Proportional to 2,275.83, 3,139.97 and 1,390.73

Step by Step Solution

1. Step 1: Write the proportion equation
   2,275.83 : 3,139.97 = 1,390.73 : x
2. Step 2: Convert to fraction form
   2,275.83/3,139.97 = 1,390.73/x
3. Step 3: Cross multiply
   2,275.83x = 3,139.97 × 1,390.73
4. Step 4: Simplify right side
   2,275.83x = 4,366,827.82
5. Step 5: Solve for x
   x = 4,366,827.82/2,275.83
6. Step 6: Final answer
   x = 1,918.78