Finding the Third Proportional to 427.69 and 645.38

Step by Step Solution

1. Step 1: Write the proportion equation
   427.69 : 645.38 = 645.38 : x
2. Step 2: Convert to fraction form
   427.69/645.38 = 645.38/x
3. Step 3: Cross multiply
   427.69x = 645.38 × 645.38
4. Step 4: Simplify right side
   427.69x = 416,508.89
5. Step 5: Solve for x
   x = 416,508.89/427.69
6. Step 6: Final answer
   x = 973.86