Finding the Third Proportional to 5,280 and 10,240

Step by Step Solution

1. Step 1: Write the proportion equation
   5,280 : 10,240 = 10,240 : x
2. Step 2: Convert to fraction form
   5,280/10,240 = 10,240/x
3. Step 3: Cross multiply
   5,280x = 10,240 × 10,240
4. Step 4: Simplify right side
   5,280x = 104,857,600
5. Step 5: Solve for x
   x = 104,857,600/5,280
6. Step 6: Final answer
   x = 19,859.39