Finding the Third Proportional to 21,423 and 43,890

Step by Step Solution

1. Step 1: Write the proportion equation
   21,423 : 43,890 = 43,890 : x
2. Step 2: Convert to fraction form
   21,423/43,890 = 43,890/x
3. Step 3: Cross multiply
   21,423x = 43,890 × 43,890
4. Step 4: Simplify right side
   21,423x = 1,926,332,100
5. Step 5: Solve for x
   x = 1,926,332,100/21,423
6. Step 6: Final answer
   x = 89,918.88