Finding the Third Proportional to 90,869 and 139,478

Step by Step Solution

1. Step 1: Write the proportion equation
   90,869 : 139,478 = 139,478 : x
2. Step 2: Convert to fraction form
   90,869/139,478 = 139,478/x
3. Step 3: Cross multiply
   90,869x = 139,478 × 139,478
4. Step 4: Simplify right side
   90,869x = 19,454,112,484
5. Step 5: Solve for x
   x = 19,454,112,484/90,869
6. Step 6: Final answer
   x = 214,089.65