Finding the Third Proportional to 90,628 and 138,328

Step by Step Solution

1. Step 1: Write the proportion equation
   90,628 : 138,328 = 138,328 : x
2. Step 2: Convert to fraction form
   90,628/138,328 = 138,328/x
3. Step 3: Cross multiply
   90,628x = 138,328 × 138,328
4. Step 4: Simplify right side
   90,628x = 19,134,635,584
5. Step 5: Solve for x
   x = 19,134,635,584/90,628
6. Step 6: Final answer
   x = 211,133.82