Finding the Third Proportional to 259,179.75 and 405,699.50

Step by Step Solution

1. Step 1: Write the proportion equation
   259,179.75 : 405,699.50 = 405,699.50 : x
2. Step 2: Convert to fraction form
   259,179.75/405,699.50 = 405,699.50/x
3. Step 3: Cross multiply
   259,179.75x = 405,699.50 × 405,699.50
4. Step 4: Simplify right side
   259,179.75x = 164,592,084,300.25
5. Step 5: Solve for x
   x = 164,592,084,300.25/259,179.75
6. Step 6: Final answer
   x = 635,049.94