Finding the Third Proportional to 256,362.50 and 397,980

Step by Step Solution

1. Step 1: Write the proportion equation
   256,362.50 : 397,980 = 397,980 : x
2. Step 2: Convert to fraction form
   256,362.50/397,980 = 397,980/x
3. Step 3: Cross multiply
   256,362.50x = 397,980 × 397,980
4. Step 4: Simplify right side
   256,362.50x = 158,388,080,400
5. Step 5: Solve for x
   x = 158,388,080,400/256,362.50
6. Step 6: Final answer
   x = 617,828.58