Finding the Third Proportional to 259,371 and 387,409.50

Step by Step Solution

1. Step 1: Write the proportion equation
   259,371 : 387,409.50 = 387,409.50 : x
2. Step 2: Convert to fraction form
   259,371/387,409.50 = 387,409.50/x
3. Step 3: Cross multiply
   259,371x = 387,409.50 × 387,409.50
4. Step 4: Simplify right side
   259,371x = 150,086,120,690.25
5. Step 5: Solve for x
   x = 150,086,120,690.25/259,371
6. Step 6: Final answer
   x = 578,654.21