Finding the Third Proportional to 308,478 and 672,990

Step by Step Solution

1. Step 1: Write the proportion equation
   308,478 : 672,990 = 672,990 : x
2. Step 2: Convert to fraction form
   308,478/672,990 = 672,990/x
3. Step 3: Cross multiply
   308,478x = 672,990 × 672,990
4. Step 4: Simplify right side
   308,478x = 452,915,540,100
5. Step 5: Solve for x
   x = 452,915,540,100/308,478
6. Step 6: Final answer
   x = 1,468,226.39