Finding the Third Proportional to 148.55 and 218.56

Step by Step Solution

1. Step 1: Write the proportion equation
   148.55 : 218.56 = 218.56 : x
2. Step 2: Convert to fraction form
   148.55/218.56 = 218.56/x
3. Step 3: Cross multiply
   148.55x = 218.56 × 218.56
4. Step 4: Simplify right side
   148.55x = 47,767.43
5. Step 5: Solve for x
   x = 47,767.43/148.55
6. Step 6: Final answer
   x = 321.55