Finding the Fourth Proportional to 2,105.73, 3,158.28 and 644.49

Step by Step Solution

1. Step 1: Write the proportion equation
   2,105.73 : 3,158.28 = 644.49 : x
2. Step 2: Convert to fraction form
   2,105.73/3,158.28 = 644.49/x
3. Step 3: Cross multiply
   2,105.73x = 3,158.28 × 644.49
4. Step 4: Simplify right side
   2,105.73x = 2,035,464.09
5. Step 5: Solve for x
   x = 2,035,464.09/2,105.73
6. Step 6: Final answer
   x = 966.63