Finding the Third Proportional to 200,816 and 428,320

Step by Step Solution

1. Step 1: Write the proportion equation
   200,816 : 428,320 = 428,320 : x
2. Step 2: Convert to fraction form
   200,816/428,320 = 428,320/x
3. Step 3: Cross multiply
   200,816x = 428,320 × 428,320
4. Step 4: Simplify right side
   200,816x = 183,458,022,400
5. Step 5: Solve for x
   x = 183,458,022,400/200,816
6. Step 6: Final answer
   x = 913,562.78