Finding the Third Proportional to 628.50 and 1,380

Step by Step Solution

1. Step 1: Write the proportion equation
   628.50 : 1,380 = 1,380 : x
2. Step 2: Convert to fraction form
   628.50/1,380 = 1,380/x
3. Step 3: Cross multiply
   628.50x = 1,380 × 1,380
4. Step 4: Simplify right side
   628.50x = 1,904,400
5. Step 5: Solve for x
   x = 1,904,400/628.50
6. Step 6: Final answer
   x = 3,030.07