Finding the Third Proportional to 211.68 and 431.89

Step by Step Solution

1. Step 1: Write the proportion equation
   211.68 : 431.89 = 431.89 : x
2. Step 2: Convert to fraction form
   211.68/431.89 = 431.89/x
3. Step 3: Cross multiply
   211.68x = 431.89 × 431.89
4. Step 4: Simplify right side
   211.68x = 186,532.89
5. Step 5: Solve for x
   x = 186,532.89/211.68
6. Step 6: Final answer
   x = 881.22