Finding the Third Proportional to 215.50 and 350.50

Step by Step Solution

1. Step 1: Write the proportion equation
   215.50 : 350.50 = 350.50 : x
2. Step 2: Convert to fraction form
   215.50/350.50 = 350.50/x
3. Step 3: Cross multiply
   215.50x = 350.50 × 350.50
4. Step 4: Simplify right side
   215.50x = 122,850.25
5. Step 5: Solve for x
   x = 122,850.25/215.50
6. Step 6: Final answer
   x = 570.07