Finding the Third Proportional to 128,222.50 and 279,020.50

Step by Step Solution

1. Step 1: Write the proportion equation
   128,222.50 : 279,020.50 = 279,020.50 : x
2. Step 2: Convert to fraction form
   128,222.50/279,020.50 = 279,020.50/x
3. Step 3: Cross multiply
   128,222.50x = 279,020.50 × 279,020.50
4. Step 4: Simplify right side
   128,222.50x = 77,852,439,420.25
5. Step 5: Solve for x
   x = 77,852,439,420.25/128,222.50
6. Step 6: Final answer
   x = 607,166.76