Finding the Fourth Proportional to 1,116.37, 1,540.48 and 644.31

Step by Step Solution

1. Step 1: Write the proportion equation
   1,116.37 : 1,540.48 = 644.31 : x
2. Step 2: Convert to fraction form
   1,116.37/1,540.48 = 644.31/x
3. Step 3: Cross multiply
   1,116.37x = 1,540.48 × 644.31
4. Step 4: Simplify right side
   1,116.37x = 992,546.67
5. Step 5: Solve for x
   x = 992,546.67/1,116.37
6. Step 6: Final answer
   x = 889.08