Finding the Third Proportional to 178,512 and 390,144

Step by Step Solution

1. Step 1: Write the proportion equation
   178,512 : 390,144 = 390,144 : x
2. Step 2: Convert to fraction form
   178,512/390,144 = 390,144/x
3. Step 3: Cross multiply
   178,512x = 390,144 × 390,144
4. Step 4: Simplify right side
   178,512x = 152,212,340,736
5. Step 5: Solve for x
   x = 152,212,340,736/178,512
6. Step 6: Final answer
   x = 852,672.88