Finding the Third Proportional to 642.75 and 1,404

Step by Step Solution

1. Step 1: Write the proportion equation
   642.75 : 1,404 = 1,404 : x
2. Step 2: Convert to fraction form
   642.75/1,404 = 1,404/x
3. Step 3: Cross multiply
   642.75x = 1,404 × 1,404
4. Step 4: Simplify right side
   642.75x = 1,971,216
5. Step 5: Solve for x
   x = 1,971,216/642.75
6. Step 6: Final answer
   x = 3,066.85