Finding the Third Proportional to 258,912 and 397,390.50

Step by Step Solution

1. Step 1: Write the proportion equation
   258,912 : 397,390.50 = 397,390.50 : x
2. Step 2: Convert to fraction form
   258,912/397,390.50 = 397,390.50/x
3. Step 3: Cross multiply
   258,912x = 397,390.50 × 397,390.50
4. Step 4: Simplify right side
   258,912x = 157,919,209,490.25
5. Step 5: Solve for x
   x = 157,919,209,490.25/258,912
6. Step 6: Final answer
   x = 609,933.91