Finding the Third Proportional to 259,278 and 388,921.50

Step by Step Solution

1. Step 1: Write the proportion equation
   259,278 : 388,921.50 = 388,921.50 : x
2. Step 2: Convert to fraction form
   259,278/388,921.50 = 388,921.50/x
3. Step 3: Cross multiply
   259,278x = 388,921.50 × 388,921.50
4. Step 4: Simplify right side
   259,278x = 151,259,933,162.25
5. Step 5: Solve for x
   x = 151,259,933,162.25/259,278
6. Step 6: Final answer
   x = 583,389.00