Finding the Fourth Proportional to 1,171.94, 1,617.22 and 640.83

Step by Step Solution

1. Step 1: Write the proportion equation
   1,171.94 : 1,617.22 = 640.83 : x
2. Step 2: Convert to fraction form
   1,171.94/1,617.22 = 640.83/x
3. Step 3: Cross multiply
   1,171.94x = 1,617.22 × 640.83
4. Step 4: Simplify right side
   1,171.94x = 1,036,363.09
5. Step 5: Solve for x
   x = 1,036,363.09/1,171.94
6. Step 6: Final answer
   x = 884.31