Finding the Fourth Proportional to 2,640.72, 3,643.26 and 1,645.17

Step by Step Solution

1. Step 1: Write the proportion equation
   2,640.72 : 3,643.26 = 1,645.17 : x
2. Step 2: Convert to fraction form
   2,640.72/3,643.26 = 1,645.17/x
3. Step 3: Cross multiply
   2,640.72x = 3,643.26 × 1,645.17
4. Step 4: Simplify right side
   2,640.72x = 5,993,782.05
5. Step 5: Solve for x
   x = 5,993,782.05/2,640.72
6. Step 6: Final answer
   x = 2,269.75