Finding the Third Proportional to 85,189.50 and 128,978.25

Step by Step Solution

1. Step 1: Write the proportion equation
   85,189.50 : 128,978.25 = 128,978.25 : x
2. Step 2: Convert to fraction form
   85,189.50/128,978.25 = 128,978.25/x
3. Step 3: Cross multiply
   85,189.50x = 128,978.25 × 128,978.25
4. Step 4: Simplify right side
   85,189.50x = 16,635,388,973.06
5. Step 5: Solve for x
   x = 16,635,388,973.06/85,189.50
6. Step 6: Final answer
   x = 195,275.11