Finding the Third Proportional to 148,855.50 and 321,039

Step by Step Solution

1. Step 1: Write the proportion equation
   148,855.50 : 321,039 = 321,039 : x
2. Step 2: Convert to fraction form
   148,855.50/321,039 = 321,039/x
3. Step 3: Cross multiply
   148,855.50x = 321,039 × 321,039
4. Step 4: Simplify right side
   148,855.50x = 103,066,039,521
5. Step 5: Solve for x
   x = 103,066,039,521/148,855.50
6. Step 6: Final answer
   x = 692,389.86