Finding the Third Proportional to 140,990 and 218,453.50

Step by Step Solution

1. Step 1: Write the proportion equation
   140,990 : 218,453.50 = 218,453.50 : x
2. Step 2: Convert to fraction form
   140,990/218,453.50 = 218,453.50/x
3. Step 3: Cross multiply
   140,990x = 218,453.50 × 218,453.50
4. Step 4: Simplify right side
   140,990x = 47,721,931,662.25
5. Step 5: Solve for x
   x = 47,721,931,662.25/140,990
6. Step 6: Final answer
   x = 338,477.42