Finding the Third Proportional to 82,509 and 128,692.50

Step by Step Solution

1. Step 1: Write the proportion equation
   82,509 : 128,692.50 = 128,692.50 : x
2. Step 2: Convert to fraction form
   82,509/128,692.50 = 128,692.50/x
3. Step 3: Cross multiply
   82,509x = 128,692.50 × 128,692.50
4. Step 4: Simplify right side
   82,509x = 16,561,759,556.25
5. Step 5: Solve for x
   x = 16,561,759,556.25/82,509
6. Step 6: Final answer
   x = 200,726.70