Finding the Third Proportional to 390,067.50 and 851,916

Step by Step Solution

1. Step 1: Write the proportion equation
   390,067.50 : 851,916 = 851,916 : x
2. Step 2: Convert to fraction form
   390,067.50/851,916 = 851,916/x
3. Step 3: Cross multiply
   390,067.50x = 851,916 × 851,916
4. Step 4: Simplify right side
   390,067.50x = 725,760,871,056
5. Step 5: Solve for x
   x = 725,760,871,056/390,067.50
6. Step 6: Final answer
   x = 1,860,603.28