Finding the Third Proportional to 100.91 and 216.78

Step by Step Solution

1. Step 1: Write the proportion equation
   100.91 : 216.78 = 216.78 : x
2. Step 2: Convert to fraction form
   100.91/216.78 = 216.78/x
3. Step 3: Cross multiply
   100.91x = 216.78 × 216.78
4. Step 4: Simplify right side
   100.91x = 46,994.11
5. Step 5: Solve for x
   x = 46,994.11/100.91
6. Step 6: Final answer
   x = 465.72