Finding the Third Proportional to 411.50 and 635.50

Step by Step Solution

1. Step 1: Write the proportion equation
   411.50 : 635.50 = 635.50 : x
2. Step 2: Convert to fraction form
   411.50/635.50 = 635.50/x
3. Step 3: Cross multiply
   411.50x = 635.50 × 635.50
4. Step 4: Simplify right side
   411.50x = 403,860.25
5. Step 5: Solve for x
   x = 403,860.25/411.50
6. Step 6: Final answer
   x = 981.43