Finding the Third Proportional to 120,178.50 and 278,205

Step by Step Solution

1. Step 1: Write the proportion equation
   120,178.50 : 278,205 = 278,205 : x
2. Step 2: Convert to fraction form
   120,178.50/278,205 = 278,205/x
3. Step 3: Cross multiply
   120,178.50x = 278,205 × 278,205
4. Step 4: Simplify right side
   120,178.50x = 77,398,022,025
5. Step 5: Solve for x
   x = 77,398,022,025/120,178.50
6. Step 6: Final answer
   x = 644,025.53