Finding the Third Proportional to 555 and 1,216.50

Step by Step Solution

1. Step 1: Write the proportion equation
   555 : 1,216.50 = 1,216.50 : x
2. Step 2: Convert to fraction form
   555/1,216.50 = 1,216.50/x
3. Step 3: Cross multiply
   555x = 1,216.50 × 1,216.50
4. Step 4: Simplify right side
   555x = 1,479,872.25
5. Step 5: Solve for x
   x = 1,479,872.25/555
6. Step 6: Final answer
   x = 2,666.44