Finding the Third Proportional to 263,451 and 390,604.50

Step by Step Solution

1. Step 1: Write the proportion equation
   263,451 : 390,604.50 = 390,604.50 : x
2. Step 2: Convert to fraction form
   263,451/390,604.50 = 390,604.50/x
3. Step 3: Cross multiply
   263,451x = 390,604.50 × 390,604.50
4. Step 4: Simplify right side
   263,451x = 152,571,875,420.25
5. Step 5: Solve for x
   x = 152,571,875,420.25/263,451
6. Step 6: Final answer
   x = 579,128.09