Finding the Fourth Proportional to 2,105.52, 3,158.42 and 644.68

Step by Step Solution

1. Step 1: Write the proportion equation
   2,105.52 : 3,158.42 = 644.68 : x
2. Step 2: Convert to fraction form
   2,105.52/3,158.42 = 644.68/x
3. Step 3: Cross multiply
   2,105.52x = 3,158.42 × 644.68
4. Step 4: Simplify right side
   2,105.52x = 2,036,170.21
5. Step 5: Solve for x
   x = 2,036,170.21/2,105.52
6. Step 6: Final answer
   x = 967.06