Finding the Third Proportional to 5,280 and 10,821

Step by Step Solution

1. Step 1: Write the proportion equation
   5,280 : 10,821 = 10,821 : x
2. Step 2: Convert to fraction form
   5,280/10,821 = 10,821/x
3. Step 3: Cross multiply
   5,280x = 10,821 × 10,821
4. Step 4: Simplify right side
   5,280x = 117,094,041
5. Step 5: Solve for x
   x = 117,094,041/5,280
6. Step 6: Final answer
   x = 22,176.90