Finding the Fourth Proportional to 1,168.61, 1,612.67 and 644.63

Step by Step Solution

1. Step 1: Write the proportion equation
   1,168.61 : 1,612.67 = 644.63 : x
2. Step 2: Convert to fraction form
   1,168.61/1,612.67 = 644.63/x
3. Step 3: Cross multiply
   1,168.61x = 1,612.67 × 644.63
4. Step 4: Simplify right side
   1,168.61x = 1,039,564.18
5. Step 5: Solve for x
   x = 1,039,564.18/1,168.61
6. Step 6: Final answer
   x = 889.58