Finding the Fourth Proportional to 1,168.38, 1,612.36 and 644.40

Step by Step Solution

1. Step 1: Write the proportion equation
   1,168.38 : 1,612.36 = 644.40 : x
2. Step 2: Convert to fraction form
   1,168.38/1,612.36 = 644.40/x
3. Step 3: Cross multiply
   1,168.38x = 1,612.36 × 644.40
4. Step 4: Simplify right side
   1,168.38x = 1,039,004.78
5. Step 5: Solve for x
   x = 1,039,004.78/1,168.38
6. Step 6: Final answer
   x = 889.27