Finding the Third Proportional to 15,828 and 21,222

Step by Step Solution

1. Step 1: Write the proportion equation
   15,828 : 21,222 = 21,222 : x
2. Step 2: Convert to fraction form
   15,828/21,222 = 21,222/x
3. Step 3: Cross multiply
   15,828x = 21,222 × 21,222
4. Step 4: Simplify right side
   15,828x = 450,373,284
5. Step 5: Solve for x
   x = 450,373,284/15,828
6. Step 6: Final answer
   x = 28,454.21