Finding the Third Proportional to 120,172.50 and 278,192

Step by Step Solution

1. Step 1: Write the proportion equation
   120,172.50 : 278,192 = 278,192 : x
2. Step 2: Convert to fraction form
   120,172.50/278,192 = 278,192/x
3. Step 3: Cross multiply
   120,172.50x = 278,192 × 278,192
4. Step 4: Simplify right side
   120,172.50x = 77,390,788,864
5. Step 5: Solve for x
   x = 77,390,788,864/120,172.50
6. Step 6: Final answer
   x = 643,997.49