Finding the Third Proportional to 218.25 and 345.38

Step by Step Solution

1. Step 1: Write the proportion equation
   218.25 : 345.38 = 345.38 : x
2. Step 2: Convert to fraction form
   218.25/345.38 = 345.38/x
3. Step 3: Cross multiply
   218.25x = 345.38 × 345.38
4. Step 4: Simplify right side
   218.25x = 119,283.89
5. Step 5: Solve for x
   x = 119,283.89/218.25
6. Step 6: Final answer
   x = 546.55