Finding the Third Proportional to 389,613 and 622,420.50

Step by Step Solution

1. Step 1: Write the proportion equation
   389,613 : 622,420.50 = 622,420.50 : x
2. Step 2: Convert to fraction form
   389,613/622,420.50 = 622,420.50/x
3. Step 3: Cross multiply
   389,613x = 622,420.50 × 622,420.50
4. Step 4: Simplify right side
   389,613x = 387,407,278,820.25
5. Step 5: Solve for x
   x = 387,407,278,820.25/389,613
6. Step 6: Final answer
   x = 994,338.69