Finding the Third Proportional to 5,257.50 and 10,510.50

Step by Step Solution

1. Step 1: Write the proportion equation
   5,257.50 : 10,510.50 = 10,510.50 : x
2. Step 2: Convert to fraction form
   5,257.50/10,510.50 = 10,510.50/x
3. Step 3: Cross multiply
   5,257.50x = 10,510.50 × 10,510.50
4. Step 4: Simplify right side
   5,257.50x = 110,470,610.25
5. Step 5: Solve for x
   x = 110,470,610.25/5,257.50
6. Step 6: Final answer
   x = 21,012.00