Finding the Third Proportional to 221.50 and 317.25

Step by Step Solution

1. Step 1: Write the proportion equation
   221.50 : 317.25 = 317.25 : x
2. Step 2: Convert to fraction form
   221.50/317.25 = 317.25/x
3. Step 3: Cross multiply
   221.50x = 317.25 × 317.25
4. Step 4: Simplify right side
   221.50x = 100,647.56
5. Step 5: Solve for x
   x = 100,647.56/221.50
6. Step 6: Final answer
   x = 454.39