Finding the Third Proportional to 148,803 and 321,128

Step by Step Solution

1. Step 1: Write the proportion equation
   148,803 : 321,128 = 321,128 : x
2. Step 2: Convert to fraction form
   148,803/321,128 = 321,128/x
3. Step 3: Cross multiply
   148,803x = 321,128 × 321,128
4. Step 4: Simplify right side
   148,803x = 103,123,192,384
5. Step 5: Solve for x
   x = 103,123,192,384/148,803
6. Step 6: Final answer
   x = 693,018.23