Finding the Third Proportional to 300,020 and 438,180.50

Step by Step Solution

1. Step 1: Write the proportion equation
   300,020 : 438,180.50 = 438,180.50 : x
2. Step 2: Convert to fraction form
   300,020/438,180.50 = 438,180.50/x
3. Step 3: Cross multiply
   300,020x = 438,180.50 × 438,180.50
4. Step 4: Simplify right side
   300,020x = 192,002,150,580.25
5. Step 5: Solve for x
   x = 192,002,150,580.25/300,020
6. Step 6: Final answer
   x = 639,964.50