Finding the Fourth Proportional to 2,105.29, 3,158.50 and 644.41

Step by Step Solution

1. Step 1: Write the proportion equation
   2,105.29 : 3,158.50 = 644.41 : x
2. Step 2: Convert to fraction form
   2,105.29/3,158.50 = 644.41/x
3. Step 3: Cross multiply
   2,105.29x = 3,158.50 × 644.41
4. Step 4: Simplify right side
   2,105.29x = 2,035,368.99
5. Step 5: Solve for x
   x = 2,035,368.99/2,105.29
6. Step 6: Final answer
   x = 966.79