Finding the Third Proportional to 200,916 and 428,488

Step by Step Solution

1. Step 1: Write the proportion equation
   200,916 : 428,488 = 428,488 : x
2. Step 2: Convert to fraction form
   200,916/428,488 = 428,488/x
3. Step 3: Cross multiply
   200,916x = 428,488 × 428,488
4. Step 4: Simplify right side
   200,916x = 183,601,966,144
5. Step 5: Solve for x
   x = 183,601,966,144/200,916
6. Step 6: Final answer
   x = 913,824.51