Finding the Third Proportional to 256.50 and 342.56

Step by Step Solution

1. Step 1: Write the proportion equation
   256.50 : 342.56 = 342.56 : x
2. Step 2: Convert to fraction form
   256.50/342.56 = 342.56/x
3. Step 3: Cross multiply
   256.50x = 342.56 × 342.56
4. Step 4: Simplify right side
   256.50x = 117,349.07
5. Step 5: Solve for x
   x = 117,349.07/256.50
6. Step 6: Final answer
   x = 457.50