Finding the Third Proportional to 54.21 and 109.79

Step by Step Solution

1. Step 1: Write the proportion equation
   54.21 : 109.79 = 109.79 : x
2. Step 2: Convert to fraction form
   54.21/109.79 = 109.79/x
3. Step 3: Cross multiply
   54.21x = 109.79 × 109.79
4. Step 4: Simplify right side
   54.21x = 12,054.50
5. Step 5: Solve for x
   x = 12,054.50/54.21
6. Step 6: Final answer
   x = 222.36