Finding the Fourth Proportional to 2,105.03, 3,158.01 and 644.30

Step by Step Solution

1. Step 1: Write the proportion equation
   2,105.03 : 3,158.01 = 644.30 : x
2. Step 2: Convert to fraction form
   2,105.03/3,158.01 = 644.30/x
3. Step 3: Cross multiply
   2,105.03x = 3,158.01 × 644.30
4. Step 4: Simplify right side
   2,105.03x = 2,034,701.90
5. Step 5: Solve for x
   x = 2,034,701.90/2,105.03
6. Step 6: Final answer
   x = 966.59