Finding the Third Proportional to 89,688 and 138,792

Step by Step Solution

1. Step 1: Write the proportion equation
   89,688 : 138,792 = 138,792 : x
2. Step 2: Convert to fraction form
   89,688/138,792 = 138,792/x
3. Step 3: Cross multiply
   89,688x = 138,792 × 138,792
4. Step 4: Simplify right side
   89,688x = 19,263,219,264
5. Step 5: Solve for x
   x = 19,263,219,264/89,688
6. Step 6: Final answer
   x = 214,780.34