Finding the Fourth Proportional to 1,086.24, 1,498.92 and 644.02

Step by Step Solution

1. Step 1: Write the proportion equation
   1,086.24 : 1,498.92 = 644.02 : x
2. Step 2: Convert to fraction form
   1,086.24/1,498.92 = 644.02/x
3. Step 3: Cross multiply
   1,086.24x = 1,498.92 × 644.02
4. Step 4: Simplify right side
   1,086.24x = 965,334.46
5. Step 5: Solve for x
   x = 965,334.46/1,086.24
6. Step 6: Final answer
   x = 888.69