Finding the Third Proportional to 287,768 and 632,640

Step by Step Solution

1. Step 1: Write the proportion equation
   287,768 : 632,640 = 632,640 : x
2. Step 2: Convert to fraction form
   287,768/632,640 = 632,640/x
3. Step 3: Cross multiply
   287,768x = 632,640 × 632,640
4. Step 4: Simplify right side
   287,768x = 400,233,369,600
5. Step 5: Solve for x
   x = 400,233,369,600/287,768
6. Step 6: Final answer
   x = 1,390,819.58