Finding the Third Proportional to 303.61 and 621.42

Step by Step Solution

1. Step 1: Write the proportion equation
   303.61 : 621.42 = 621.42 : x
2. Step 2: Convert to fraction form
   303.61/621.42 = 621.42/x
3. Step 3: Cross multiply
   303.61x = 621.42 × 621.42
4. Step 4: Simplify right side
   303.61x = 386,165.15
5. Step 5: Solve for x
   x = 386,165.15/303.61
6. Step 6: Final answer
   x = 1,271.91