Finding the Third Proportional to 90,138 and 140,128.50

Step by Step Solution

1. Step 1: Write the proportion equation
   90,138 : 140,128.50 = 140,128.50 : x
2. Step 2: Convert to fraction form
   90,138/140,128.50 = 140,128.50/x
3. Step 3: Cross multiply
   90,138x = 140,128.50 × 140,128.50
4. Step 4: Simplify right side
   90,138x = 19,635,996,512.25
5. Step 5: Solve for x
   x = 19,635,996,512.25/90,138
6. Step 6: Final answer
   x = 217,843.71