Finding the Third Proportional to 301,822.50 and 639,619.50

Step by Step Solution

1. Step 1: Write the proportion equation
   301,822.50 : 639,619.50 = 639,619.50 : x
2. Step 2: Convert to fraction form
   301,822.50/639,619.50 = 639,619.50/x
3. Step 3: Cross multiply
   301,822.50x = 639,619.50 × 639,619.50
4. Step 4: Simplify right side
   301,822.50x = 409,113,104,780.25
5. Step 5: Solve for x
   x = 409,113,104,780.25/301,822.50
6. Step 6: Final answer
   x = 1,355,475.83