Finding the Third Proportional to 200,409 and 280,198.50

Step by Step Solution

1. Step 1: Write the proportion equation
   200,409 : 280,198.50 = 280,198.50 : x
2. Step 2: Convert to fraction form
   200,409/280,198.50 = 280,198.50/x
3. Step 3: Cross multiply
   200,409x = 280,198.50 × 280,198.50
4. Step 4: Simplify right side
   200,409x = 78,511,199,402.25
5. Step 5: Solve for x
   x = 78,511,199,402.25/200,409
6. Step 6: Final answer
   x = 391,754.86