Finding the Third Proportional to 217.69 and 288.56

Step by Step Solution

1. Step 1: Write the proportion equation
   217.69 : 288.56 = 288.56 : x
2. Step 2: Convert to fraction form
   217.69/288.56 = 288.56/x
3. Step 3: Cross multiply
   217.69x = 288.56 × 288.56
4. Step 4: Simplify right side
   217.69x = 83,268.32
5. Step 5: Solve for x
   x = 83,268.32/217.69
6. Step 6: Final answer
   x = 382.51