Finding the Third Proportional to 21,120 and 43,428

Step by Step Solution

1. Step 1: Write the proportion equation
   21,120 : 43,428 = 43,428 : x
2. Step 2: Convert to fraction form
   21,120/43,428 = 43,428/x
3. Step 3: Cross multiply
   21,120x = 43,428 × 43,428
4. Step 4: Simplify right side
   21,120x = 1,885,991,184
5. Step 5: Solve for x
   x = 1,885,991,184/21,120
6. Step 6: Final answer
   x = 89,298.83