Finding the Third Proportional to 389,858 and 810,360

Step by Step Solution

1. Step 1: Write the proportion equation
   389,858 : 810,360 = 810,360 : x
2. Step 2: Convert to fraction form
   389,858/810,360 = 810,360/x
3. Step 3: Cross multiply
   389,858x = 810,360 × 810,360
4. Step 4: Simplify right side
   389,858x = 656,683,329,600
5. Step 5: Solve for x
   x = 656,683,329,600/389,858
6. Step 6: Final answer
   x = 1,684,416.71