Finding the Third Proportional to 389,448 and 818,258.63

Step by Step Solution

1. Step 1: Write the proportion equation
   389,448 : 818,258.63 = 818,258.63 : x
2. Step 2: Convert to fraction form
   389,448/818,258.63 = 818,258.63/x
3. Step 3: Cross multiply
   389,448x = 818,258.63 × 818,258.63
4. Step 4: Simplify right side
   389,448x = 669,547,177,386.89
5. Step 5: Solve for x
   x = 669,547,177,386.89/389,448
6. Step 6: Final answer
   x = 1,719,220.99