Finding the Third Proportional to 641.25 and 1,386

Step by Step Solution

1. Step 1: Write the proportion equation
   641.25 : 1,386 = 1,386 : x
2. Step 2: Convert to fraction form
   641.25/1,386 = 1,386/x
3. Step 3: Cross multiply
   641.25x = 1,386 × 1,386
4. Step 4: Simplify right side
   641.25x = 1,920,996
5. Step 5: Solve for x
   x = 1,920,996/641.25
6. Step 6: Final answer
   x = 2,995.71