Finding the Fourth Proportional to 1,116.41, 1,540.62 and 644.27

Step by Step Solution

1. Step 1: Write the proportion equation
   1,116.41 : 1,540.62 = 644.27 : x
2. Step 2: Convert to fraction form
   1,116.41/1,540.62 = 644.27/x
3. Step 3: Cross multiply
   1,116.41x = 1,540.62 × 644.27
4. Step 4: Simplify right side
   1,116.41x = 992,579.10
5. Step 5: Solve for x
   x = 992,579.10/1,116.41
6. Step 6: Final answer
   x = 889.09