Finding the Third Proportional to 86,918 and 209,321.50

Step by Step Solution

1. Step 1: Write the proportion equation
   86,918 : 209,321.50 = 209,321.50 : x
2. Step 2: Convert to fraction form
   86,918/209,321.50 = 209,321.50/x
3. Step 3: Cross multiply
   86,918x = 209,321.50 × 209,321.50
4. Step 4: Simplify right side
   86,918x = 43,815,490,362.25
5. Step 5: Solve for x
   x = 43,815,490,362.25/86,918
6. Step 6: Final answer
   x = 504,101.46