Finding the Third Proportional to 200,268 and 309,990

Step by Step Solution

1. Step 1: Write the proportion equation
   200,268 : 309,990 = 309,990 : x
2. Step 2: Convert to fraction form
   200,268/309,990 = 309,990/x
3. Step 3: Cross multiply
   200,268x = 309,990 × 309,990
4. Step 4: Simplify right side
   200,268x = 96,093,800,100
5. Step 5: Solve for x
   x = 96,093,800,100/200,268
6. Step 6: Final answer
   x = 479,826.03