Finding the Fourth Proportional to 2,105.46, 3,158.06 and 644.50

Step by Step Solution

1. Step 1: Write the proportion equation
   2,105.46 : 3,158.06 = 644.50 : x
2. Step 2: Convert to fraction form
   2,105.46/3,158.06 = 644.50/x
3. Step 3: Cross multiply
   2,105.46x = 3,158.06 × 644.50
4. Step 4: Simplify right side
   2,105.46x = 2,035,369.67
5. Step 5: Solve for x
   x = 2,035,369.67/2,105.46
6. Step 6: Final answer
   x = 966.71