Finding the Third Proportional to 397,239 and 815,407.50

Step by Step Solution

1. Step 1: Write the proportion equation
   397,239 : 815,407.50 = 815,407.50 : x
2. Step 2: Convert to fraction form
   397,239/815,407.50 = 815,407.50/x
3. Step 3: Cross multiply
   397,239x = 815,407.50 × 815,407.50
4. Step 4: Simplify right side
   397,239x = 664,889,391,056.25
5. Step 5: Solve for x
   x = 664,889,391,056.25/397,239
6. Step 6: Final answer
   x = 1,673,776.72