Finding the Fourth Proportional to 10,586.72, 15,878.88 and 2,689.20

Step by Step Solution

1. Step 1: Write the proportion equation
   10,586.72 : 15,878.88 = 2,689.20 : x
2. Step 2: Convert to fraction form
   10,586.72/15,878.88 = 2,689.20/x
3. Step 3: Cross multiply
   10,586.72x = 15,878.88 × 2,689.20
4. Step 4: Simplify right side
   10,586.72x = 42,701,484.10
5. Step 5: Solve for x
   x = 42,701,484.10/10,586.72
6. Step 6: Final answer
   x = 4,033.50