Finding the Third Proportional to 150,210 and 321,742.50

Step by Step Solution

1. Step 1: Write the proportion equation
   150,210 : 321,742.50 = 321,742.50 : x
2. Step 2: Convert to fraction form
   150,210/321,742.50 = 321,742.50/x
3. Step 3: Cross multiply
   150,210x = 321,742.50 × 321,742.50
4. Step 4: Simplify right side
   150,210x = 103,518,236,306.25
5. Step 5: Solve for x
   x = 103,518,236,306.25/150,210
6. Step 6: Final answer
   x = 689,156.76