Finding the Third Proportional to 200,538 and 428,136

Step by Step Solution

1. Step 1: Write the proportion equation
   200,538 : 428,136 = 428,136 : x
2. Step 2: Convert to fraction form
   200,538/428,136 = 428,136/x
3. Step 3: Cross multiply
   200,538x = 428,136 × 428,136
4. Step 4: Simplify right side
   200,538x = 183,300,434,496
5. Step 5: Solve for x
   x = 183,300,434,496/200,538
6. Step 6: Final answer
   x = 914,043.40