Finding the Fourth Proportional to 2,103.61, 3,155.79 and 870.35

Step by Step Solution

1. Step 1: Write the proportion equation
   2,103.61 : 3,155.79 = 870.35 : x
2. Step 2: Convert to fraction form
   2,103.61/3,155.79 = 870.35/x
3. Step 3: Cross multiply
   2,103.61x = 3,155.79 × 870.35
4. Step 4: Simplify right side
   2,103.61x = 2,746,641.83
5. Step 5: Solve for x
   x = 2,746,641.83/2,103.61
6. Step 6: Final answer
   x = 1,305.68