Finding the Fourth Proportional to 2,108.69, 3,159.39 and 1,640.32

Step by Step Solution

1. Step 1: Write the proportion equation
   2,108.69 : 3,159.39 = 1,640.32 : x
2. Step 2: Convert to fraction form
   2,108.69/3,159.39 = 1,640.32/x
3. Step 3: Cross multiply
   2,108.69x = 3,159.39 × 1,640.32
4. Step 4: Simplify right side
   2,108.69x = 5,182,410.60
5. Step 5: Solve for x
   x = 5,182,410.60/2,108.69
6. Step 6: Final answer
   x = 2,457.64