Finding the Third Proportional to 427.25 and 647.50

Step by Step Solution

1. Step 1: Write the proportion equation
   427.25 : 647.50 = 647.50 : x
2. Step 2: Convert to fraction form
   427.25/647.50 = 647.50/x
3. Step 3: Cross multiply
   427.25x = 647.50 × 647.50
4. Step 4: Simplify right side
   427.25x = 419,256.25
5. Step 5: Solve for x
   x = 419,256.25/427.25
6. Step 6: Final answer
   x = 981.29