Finding the Fourth Proportional to 3,515.72, 5,280.41 and 2,587.61

Step by Step Solution

1. Step 1: Write the proportion equation
   3,515.72 : 5,280.41 = 2,587.61 : x
2. Step 2: Convert to fraction form
   3,515.72/5,280.41 = 2,587.61/x
3. Step 3: Cross multiply
   3,515.72x = 5,280.41 × 2,587.61
4. Step 4: Simplify right side
   3,515.72x = 13,663,641.72
5. Step 5: Solve for x
   x = 13,663,641.72/3,515.72
6. Step 6: Final answer
   x = 3,886.44