Finding the Fourth Proportional to 1,168.15, 1,612.05 and 644.18

Step by Step Solution

1. Step 1: Write the proportion equation
   1,168.15 : 1,612.05 = 644.18 : x
2. Step 2: Convert to fraction form
   1,168.15/1,612.05 = 644.18/x
3. Step 3: Cross multiply
   1,168.15x = 1,612.05 × 644.18
4. Step 4: Simplify right side
   1,168.15x = 1,038,450.37
5. Step 5: Solve for x
   x = 1,038,450.37/1,168.15
6. Step 6: Final answer
   x = 888.97