Finding the Third Proportional to 300.38 and 644.25

Step by Step Solution

1. Step 1: Write the proportion equation
   300.38 : 644.25 = 644.25 : x
2. Step 2: Convert to fraction form
   300.38/644.25 = 644.25/x
3. Step 3: Cross multiply
   300.38x = 644.25 × 644.25
4. Step 4: Simplify right side
   300.38x = 415,058.06
5. Step 5: Solve for x
   x = 415,058.06/300.38
6. Step 6: Final answer
   x = 1,381.80