Finding the Fourth Proportional to 2,145.82, 3,218.87 and 685.08

Step by Step Solution

1. Step 1: Write the proportion equation
   2,145.82 : 3,218.87 = 685.08 : x
2. Step 2: Convert to fraction form
   2,145.82/3,218.87 = 685.08/x
3. Step 3: Cross multiply
   2,145.82x = 3,218.87 × 685.08
4. Step 4: Simplify right side
   2,145.82x = 2,205,185.17
5. Step 5: Solve for x
   x = 2,205,185.17/2,145.82
6. Step 6: Final answer
   x = 1,027.67