Finding the Third Proportional to 643.88 and 1,401.94

Step by Step Solution

1. Step 1: Write the proportion equation
   643.88 : 1,401.94 = 1,401.94 : x
2. Step 2: Convert to fraction form
   643.88/1,401.94 = 1,401.94/x
3. Step 3: Cross multiply
   643.88x = 1,401.94 × 1,401.94
4. Step 4: Simplify right side
   643.88x = 1,965,428.75
5. Step 5: Solve for x
   x = 1,965,428.75/643.88
6. Step 6: Final answer
   x = 3,052.50