Finding the Third Proportional to 217.69 and 425.25

Step by Step Solution

1. Step 1: Write the proportion equation
   217.69 : 425.25 = 425.25 : x
2. Step 2: Convert to fraction form
   217.69/425.25 = 425.25/x
3. Step 3: Cross multiply
   217.69x = 425.25 × 425.25
4. Step 4: Simplify right side
   217.69x = 180,837.56
5. Step 5: Solve for x
   x = 180,837.56/217.69
6. Step 6: Final answer
   x = 830.72