Finding the Third Proportional to 10,989 and 21,438

Step by Step Solution

1. Step 1: Write the proportion equation
   10,989 : 21,438 = 21,438 : x
2. Step 2: Convert to fraction form
   10,989/21,438 = 21,438/x
3. Step 3: Cross multiply
   10,989x = 21,438 × 21,438
4. Step 4: Simplify right side
   10,989x = 459,587,844
5. Step 5: Solve for x
   x = 459,587,844/10,989
6. Step 6: Final answer
   x = 41,822.54