Finding the Third Proportional to 426.38 and 644.06

Step by Step Solution

1. Step 1: Write the proportion equation
   426.38 : 644.06 = 644.06 : x
2. Step 2: Convert to fraction form
   426.38/644.06 = 644.06/x
3. Step 3: Cross multiply
   426.38x = 644.06 × 644.06
4. Step 4: Simplify right side
   426.38x = 414,816.50
5. Step 5: Solve for x
   x = 414,816.50/426.38
6. Step 6: Final answer
   x = 972.89