Finding the Third Proportional to 100.78 and 211.22

Step by Step Solution

1. Step 1: Write the proportion equation
   100.78 : 211.22 = 211.22 : x
2. Step 2: Convert to fraction form
   100.78/211.22 = 211.22/x
3. Step 3: Cross multiply
   100.78x = 211.22 × 211.22
4. Step 4: Simplify right side
   100.78x = 44,613.36
5. Step 5: Solve for x
   x = 44,613.36/100.78
6. Step 6: Final answer
   x = 442.68