Finding the Third Proportional to 215.50 and 442.50

Step by Step Solution

1. Step 1: Write the proportion equation
   215.50 : 442.50 = 442.50 : x
2. Step 2: Convert to fraction form
   215.50/442.50 = 442.50/x
3. Step 3: Cross multiply
   215.50x = 442.50 × 442.50
4. Step 4: Simplify right side
   215.50x = 195,806.25
5. Step 5: Solve for x
   x = 195,806.25/215.50
6. Step 6: Final answer
   x = 908.61