Finding the Third Proportional to 144,398 and 215,400

Step by Step Solution

1. Step 1: Write the proportion equation
   144,398 : 215,400 = 215,400 : x
2. Step 2: Convert to fraction form
   144,398/215,400 = 215,400/x
3. Step 3: Cross multiply
   144,398x = 215,400 × 215,400
4. Step 4: Simplify right side
   144,398x = 46,397,160,000
5. Step 5: Solve for x
   x = 46,397,160,000/144,398
6. Step 6: Final answer
   x = 321,314.42