Finding the Third Proportional to 1,021.68 and 2,139.54

Step by Step Solution

1. Step 1: Write the proportion equation
   1,021.68 : 2,139.54 = 2,139.54 : x
2. Step 2: Convert to fraction form
   1,021.68/2,139.54 = 2,139.54/x
3. Step 3: Cross multiply
   1,021.68x = 2,139.54 × 2,139.54
4. Step 4: Simplify right side
   1,021.68x = 4,577,627.40
5. Step 5: Solve for x
   x = 4,577,627.40/1,021.68
6. Step 6: Final answer
   x = 4,480.51