Finding the Third Proportional to 287,158 and 631,364

Step by Step Solution

1. Step 1: Write the proportion equation
   287,158 : 631,364 = 631,364 : x
2. Step 2: Convert to fraction form
   287,158/631,364 = 631,364/x
3. Step 3: Cross multiply
   287,158x = 631,364 × 631,364
4. Step 4: Simplify right side
   287,158x = 398,620,500,496
5. Step 5: Solve for x
   x = 398,620,500,496/287,158
6. Step 6: Final answer
   x = 1,388,157.39