Finding the Third Proportional to 150,405 and 321,106.50

Step by Step Solution

1. Step 1: Write the proportion equation
   150,405 : 321,106.50 = 321,106.50 : x
2. Step 2: Convert to fraction form
   150,405/321,106.50 = 321,106.50/x
3. Step 3: Cross multiply
   150,405x = 321,106.50 × 321,106.50
4. Step 4: Simplify right side
   150,405x = 103,109,384,342.25
5. Step 5: Solve for x
   x = 103,109,384,342.25/150,405
6. Step 6: Final answer
   x = 685,544.92