Finding the Third Proportional to 5,128.45 and 10,237.78

Step by Step Solution

1. Step 1: Write the proportion equation
   5,128.45 : 10,237.78 = 10,237.78 : x
2. Step 2: Convert to fraction form
   5,128.45/10,237.78 = 10,237.78/x
3. Step 3: Cross multiply
   5,128.45x = 10,237.78 × 10,237.78
4. Step 4: Simplify right side
   5,128.45x = 104,812,164.92
5. Step 5: Solve for x
   x = 104,812,164.92/5,128.45
6. Step 6: Final answer
   x = 20,437.38