Finding the Fourth Proportional to 2,587.32, 3,880.50 and 855.72

Step by Step Solution

1. Step 1: Write the proportion equation
   2,587.32 : 3,880.50 = 855.72 : x
2. Step 2: Convert to fraction form
   2,587.32/3,880.50 = 855.72/x
3. Step 3: Cross multiply
   2,587.32x = 3,880.50 × 855.72
4. Step 4: Simplify right side
   2,587.32x = 3,320,621.46
5. Step 5: Solve for x
   x = 3,320,621.46/2,587.32
6. Step 6: Final answer
   x = 1,283.42