Finding the Third Proportional to 259,686 and 405,931.50

Step by Step Solution

1. Step 1: Write the proportion equation
   259,686 : 405,931.50 = 405,931.50 : x
2. Step 2: Convert to fraction form
   259,686/405,931.50 = 405,931.50/x
3. Step 3: Cross multiply
   259,686x = 405,931.50 × 405,931.50
4. Step 4: Simplify right side
   259,686x = 164,780,382,692.25
5. Step 5: Solve for x
   x = 164,780,382,692.25/259,686
6. Step 6: Final answer
   x = 634,537.03