Finding the Fourth Proportional to 1,116.10, 1,540.32 and 644.14

Step by Step Solution

1. Step 1: Write the proportion equation
   1,116.10 : 1,540.32 = 644.14 : x
2. Step 2: Convert to fraction form
   1,116.10/1,540.32 = 644.14/x
3. Step 3: Cross multiply
   1,116.10x = 1,540.32 × 644.14
4. Step 4: Simplify right side
   1,116.10x = 992,181.72
5. Step 5: Solve for x
   x = 992,181.72/1,116.10
6. Step 6: Final answer
   x = 888.97