Finding the Third Proportional to 90,990 and 139,383

Step by Step Solution

1. Step 1: Write the proportion equation
   90,990 : 139,383 = 139,383 : x
2. Step 2: Convert to fraction form
   90,990/139,383 = 139,383/x
3. Step 3: Cross multiply
   90,990x = 139,383 × 139,383
4. Step 4: Simplify right side
   90,990x = 19,427,620,689
5. Step 5: Solve for x
   x = 19,427,620,689/90,990
6. Step 6: Final answer
   x = 213,513.80