Finding the Third Proportional to 21,142 and 28,478

Step by Step Solution

1. Step 1: Write the proportion equation
   21,142 : 28,478 = 28,478 : x
2. Step 2: Convert to fraction form
   21,142/28,478 = 28,478/x
3. Step 3: Cross multiply
   21,142x = 28,478 × 28,478
4. Step 4: Simplify right side
   21,142x = 810,996,484
5. Step 5: Solve for x
   x = 810,996,484/21,142
6. Step 6: Final answer
   x = 38,359.50