Finding the Fourth Proportional to 2,105.12, 3,158.04 and 644.12

Step by Step Solution

1. Step 1: Write the proportion equation
   2,105.12 : 3,158.04 = 644.12 : x
2. Step 2: Convert to fraction form
   2,105.12/3,158.04 = 644.12/x
3. Step 3: Cross multiply
   2,105.12x = 3,158.04 × 644.12
4. Step 4: Simplify right side
   2,105.12x = 2,034,156.72
5. Step 5: Solve for x
   x = 2,034,156.72/2,105.12
6. Step 6: Final answer
   x = 966.29