Finding the Third Proportional to 427.50 and 663.89

Step by Step Solution

1. Step 1: Write the proportion equation
   427.50 : 663.89 = 663.89 : x
2. Step 2: Convert to fraction form
   427.50/663.89 = 663.89/x
3. Step 3: Cross multiply
   427.50x = 663.89 × 663.89
4. Step 4: Simplify right side
   427.50x = 440,750.76
5. Step 5: Solve for x
   x = 440,750.76/427.50
6. Step 6: Final answer
   x = 1,031.00