Finding the Third Proportional to 321,166.50 and 691,662

Step by Step Solution

1. Step 1: Write the proportion equation
   321,166.50 : 691,662 = 691,662 : x
2. Step 2: Convert to fraction form
   321,166.50/691,662 = 691,662/x
3. Step 3: Cross multiply
   321,166.50x = 691,662 × 691,662
4. Step 4: Simplify right side
   321,166.50x = 478,396,322,244
5. Step 5: Solve for x
   x = 478,396,322,244/321,166.50
6. Step 6: Final answer
   x = 1,489,558.60