Finding the Third Proportional to 262,840 and 402,144

Step by Step Solution

1. Step 1: Write the proportion equation
   262,840 : 402,144 = 402,144 : x
2. Step 2: Convert to fraction form
   262,840/402,144 = 402,144/x
3. Step 3: Cross multiply
   262,840x = 402,144 × 402,144
4. Step 4: Simplify right side
   262,840x = 161,719,796,736
5. Step 5: Solve for x
   x = 161,719,796,736/262,840
6. Step 6: Final answer
   x = 615,278.48