Finding the Fourth Proportional to 1,033.80, 1,426.61 and 640.82

Step by Step Solution

1. Step 1: Write the proportion equation
   1,033.80 : 1,426.61 = 640.82 : x
2. Step 2: Convert to fraction form
   1,033.80/1,426.61 = 640.82/x
3. Step 3: Cross multiply
   1,033.80x = 1,426.61 × 640.82
4. Step 4: Simplify right side
   1,033.80x = 914,189.88
5. Step 5: Solve for x
   x = 914,189.88/1,033.80
6. Step 6: Final answer
   x = 884.30