Finding the Third Proportional to 138,646 and 300,458

Step by Step Solution

1. Step 1: Write the proportion equation
   138,646 : 300,458 = 300,458 : x
2. Step 2: Convert to fraction form
   138,646/300,458 = 300,458/x
3. Step 3: Cross multiply
   138,646x = 300,458 × 300,458
4. Step 4: Simplify right side
   138,646x = 90,275,009,764
5. Step 5: Solve for x
   x = 90,275,009,764/138,646
6. Step 6: Final answer
   x = 651,118.75