Finding the Third Proportional to 211.78 and 433.69

Step by Step Solution

1. Step 1: Write the proportion equation
   211.78 : 433.69 = 433.69 : x
2. Step 2: Convert to fraction form
   211.78/433.69 = 433.69/x
3. Step 3: Cross multiply
   211.78x = 433.69 × 433.69
4. Step 4: Simplify right side
   211.78x = 188,084.85
5. Step 5: Solve for x
   x = 188,084.85/211.78
6. Step 6: Final answer
   x = 888.11