Finding the Third Proportional to 128,067.75 and 139,549.50

Step by Step Solution

1. Step 1: Write the proportion equation
   128,067.75 : 139,549.50 = 139,549.50 : x
2. Step 2: Convert to fraction form
   128,067.75/139,549.50 = 139,549.50/x
3. Step 3: Cross multiply
   128,067.75x = 139,549.50 × 139,549.50
4. Step 4: Simplify right side
   128,067.75x = 19,474,062,950.25
5. Step 5: Solve for x
   x = 19,474,062,950.25/128,067.75
6. Step 6: Final answer
   x = 152,060.63