Finding the Third Proportional to 277,860 and 420,691.50

Step by Step Solution

1. Step 1: Write the proportion equation
   277,860 : 420,691.50 = 420,691.50 : x
2. Step 2: Convert to fraction form
   277,860/420,691.50 = 420,691.50/x
3. Step 3: Cross multiply
   277,860x = 420,691.50 × 420,691.50
4. Step 4: Simplify right side
   277,860x = 176,981,338,172.25
5. Step 5: Solve for x
   x = 176,981,338,172.25/277,860
6. Step 6: Final answer
   x = 636,944.28