Finding the Fourth Proportional to 1,086.01, 1,498.88 and 644.06

Step by Step Solution

1. Step 1: Write the proportion equation
   1,086.01 : 1,498.88 = 644.06 : x
2. Step 2: Convert to fraction form
   1,086.01/1,498.88 = 644.06/x
3. Step 3: Cross multiply
   1,086.01x = 1,498.88 × 644.06
4. Step 4: Simplify right side
   1,086.01x = 965,374.01
5. Step 5: Solve for x
   x = 965,374.01/1,086.01
6. Step 6: Final answer
   x = 888.92