Finding the Fourth Proportional to 1,911.99, 2,640.23 and 1,205.09

Step by Step Solution

1. Step 1: Write the proportion equation
   1,911.99 : 2,640.23 = 1,205.09 : x
2. Step 2: Convert to fraction form
   1,911.99/2,640.23 = 1,205.09/x
3. Step 3: Cross multiply
   1,911.99x = 2,640.23 × 1,205.09
4. Step 4: Simplify right side
   1,911.99x = 3,181,724.82
5. Step 5: Solve for x
   x = 3,181,724.82/1,911.99
6. Step 6: Final answer
   x = 1,664.09