Finding the Third Proportional to 150,699 and 321,390

Step by Step Solution

1. Step 1: Write the proportion equation
   150,699 : 321,390 = 321,390 : x
2. Step 2: Convert to fraction form
   150,699/321,390 = 321,390/x
3. Step 3: Cross multiply
   150,699x = 321,390 × 321,390
4. Step 4: Simplify right side
   150,699x = 103,291,532,100
5. Step 5: Solve for x
   x = 103,291,532,100/150,699
6. Step 6: Final answer
   x = 685,416.17