Finding the Fourth Proportional to 2,103.74, 3,155.67 and 870.30

Step by Step Solution

1. Step 1: Write the proportion equation
   2,103.74 : 3,155.67 = 870.30 : x
2. Step 2: Convert to fraction form
   2,103.74/3,155.67 = 870.30/x
3. Step 3: Cross multiply
   2,103.74x = 3,155.67 × 870.30
4. Step 4: Simplify right side
   2,103.74x = 2,746,379.60
5. Step 5: Solve for x
   x = 2,746,379.60/2,103.74
6. Step 6: Final answer
   x = 1,305.48