Finding the Fourth Proportional to 3,878.89, 5,355.42 and 2,621.67

Step by Step Solution

1. Step 1: Write the proportion equation
   3,878.89 : 5,355.42 = 2,621.67 : x
2. Step 2: Convert to fraction form
   3,878.89/5,355.42 = 2,621.67/x
3. Step 3: Cross multiply
   3,878.89x = 5,355.42 × 2,621.67
4. Step 4: Simplify right side
   3,878.89x = 14,040,114.04
5. Step 5: Solve for x
   x = 14,040,114.04/3,878.89
6. Step 6: Final answer
   x = 3,619.62