Finding the Third Proportional to 290,836 and 623,144

Step by Step Solution

1. Step 1: Write the proportion equation
   290,836 : 623,144 = 623,144 : x
2. Step 2: Convert to fraction form
   290,836/623,144 = 623,144/x
3. Step 3: Cross multiply
   290,836x = 623,144 × 623,144
4. Step 4: Simplify right side
   290,836x = 388,308,444,736
5. Step 5: Solve for x
   x = 388,308,444,736/290,836
6. Step 6: Final answer
   x = 1,335,145.73