Finding the Fourth Proportional to 1,168.31, 1,612.37 and 644.45

Step by Step Solution

1. Step 1: Write the proportion equation
   1,168.31 : 1,612.37 = 644.45 : x
2. Step 2: Convert to fraction form
   1,168.31/1,612.37 = 644.45/x
3. Step 3: Cross multiply
   1,168.31x = 1,612.37 × 644.45
4. Step 4: Simplify right side
   1,168.31x = 1,039,085.40
5. Step 5: Solve for x
   x = 1,039,085.40/1,168.31
6. Step 6: Final answer
   x = 889.39