Finding the Fourth Proportional to 2,601.60, 3,902.16 and 870.24

Step by Step Solution

1. Step 1: Write the proportion equation
   2,601.60 : 3,902.16 = 870.24 : x
2. Step 2: Convert to fraction form
   2,601.60/3,902.16 = 870.24/x
3. Step 3: Cross multiply
   2,601.60x = 3,902.16 × 870.24
4. Step 4: Simplify right side
   2,601.60x = 3,395,815.72
5. Step 5: Solve for x
   x = 3,395,815.72/2,601.60
6. Step 6: Final answer
   x = 1,305.28