Finding the Third Proportional to 213,421.50 and 309,116.25

Step by Step Solution

1. Step 1: Write the proportion equation
   213,421.50 : 309,116.25 = 309,116.25 : x
2. Step 2: Convert to fraction form
   213,421.50/309,116.25 = 309,116.25/x
3. Step 3: Cross multiply
   213,421.50x = 309,116.25 × 309,116.25
4. Step 4: Simplify right side
   213,421.50x = 95,552,856,014.06
5. Step 5: Solve for x
   x = 95,552,856,014.06/213,421.50
6. Step 6: Final answer
   x = 447,718.98