Finding the Fourth Proportional to 2,616.40, 3,609.90 and 1,621.72

Step by Step Solution

1. Step 1: Write the proportion equation
   2,616.40 : 3,609.90 = 1,621.72 : x
2. Step 2: Convert to fraction form
   2,616.40/3,609.90 = 1,621.72/x
3. Step 3: Cross multiply
   2,616.40x = 3,609.90 × 1,621.72
4. Step 4: Simplify right side
   2,616.40x = 5,854,247.03
5. Step 5: Solve for x
   x = 5,854,247.03/2,616.40
6. Step 6: Final answer
   x = 2,237.52