Finding the Fourth Proportional to 2,103.77, 3,155.31 and 870.72

Step by Step Solution

1. Step 1: Write the proportion equation
   2,103.77 : 3,155.31 = 870.72 : x
2. Step 2: Convert to fraction form
   2,103.77/3,155.31 = 870.72/x
3. Step 3: Cross multiply
   2,103.77x = 3,155.31 × 870.72
4. Step 4: Simplify right side
   2,103.77x = 2,747,391.52
5. Step 5: Solve for x
   x = 2,747,391.52/2,103.77
6. Step 6: Final answer
   x = 1,305.94