Finding the Third Proportional to 558.56 and 1,320.56

Step by Step Solution

1. Step 1: Write the proportion equation
   558.56 : 1,320.56 = 1,320.56 : x
2. Step 2: Convert to fraction form
   558.56/1,320.56 = 1,320.56/x
3. Step 3: Cross multiply
   558.56x = 1,320.56 × 1,320.56
4. Step 4: Simplify right side
   558.56x = 1,743,885.32
5. Step 5: Solve for x
   x = 1,743,885.32/558.56
6. Step 6: Final answer
   x = 3,122.10