Finding the Third Proportional to 5,128 and 7,922.50

Step by Step Solution

1. Step 1: Write the proportion equation
   5,128 : 7,922.50 = 7,922.50 : x
2. Step 2: Convert to fraction form
   5,128/7,922.50 = 7,922.50/x
3. Step 3: Cross multiply
   5,128x = 7,922.50 × 7,922.50
4. Step 4: Simplify right side
   5,128x = 62,766,006.25
5. Step 5: Solve for x
   x = 62,766,006.25/5,128
6. Step 6: Final answer
   x = 12,239.86