Finding the Third Proportional to 300.56 and 644.81

Step by Step Solution

1. Step 1: Write the proportion equation
   300.56 : 644.81 = 644.81 : x
2. Step 2: Convert to fraction form
   300.56/644.81 = 644.81/x
3. Step 3: Cross multiply
   300.56x = 644.81 × 644.81
4. Step 4: Simplify right side
   300.56x = 415,783.16
5. Step 5: Solve for x
   x = 415,783.16/300.56
6. Step 6: Final answer
   x = 1,383.35