Finding the Third Proportional to 290,288 and 448,540

Step by Step Solution

1. Step 1: Write the proportion equation
   290,288 : 448,540 = 448,540 : x
2. Step 2: Convert to fraction form
   290,288/448,540 = 448,540/x
3. Step 3: Cross multiply
   290,288x = 448,540 × 448,540
4. Step 4: Simplify right side
   290,288x = 201,188,131,600
5. Step 5: Solve for x
   x = 201,188,131,600/290,288
6. Step 6: Final answer
   x = 693,063.89