Finding the Third Proportional to 210.50 and 411.25

Step by Step Solution

1. Step 1: Write the proportion equation
   210.50 : 411.25 = 411.25 : x
2. Step 2: Convert to fraction form
   210.50/411.25 = 411.25/x
3. Step 3: Cross multiply
   210.50x = 411.25 × 411.25
4. Step 4: Simplify right side
   210.50x = 169,126.56
5. Step 5: Solve for x
   x = 169,126.56/210.50
6. Step 6: Final answer
   x = 803.45