Finding the Fourth Proportional to 1,168.20, 1,612.17 and 644.27

Step by Step Solution

1. Step 1: Write the proportion equation
   1,168.20 : 1,612.17 = 644.27 : x
2. Step 2: Convert to fraction form
   1,168.20/1,612.17 = 644.27/x
3. Step 3: Cross multiply
   1,168.20x = 1,612.17 × 644.27
4. Step 4: Simplify right side
   1,168.20x = 1,038,664.71
5. Step 5: Solve for x
   x = 1,038,664.71/1,168.20
6. Step 6: Final answer
   x = 889.12