Finding the Third Proportional to 211.78 and 458.72

Step by Step Solution

1. Step 1: Write the proportion equation
   211.78 : 458.72 = 458.72 : x
2. Step 2: Convert to fraction form
   211.78/458.72 = 458.72/x
3. Step 3: Cross multiply
   211.78x = 458.72 × 458.72
4. Step 4: Simplify right side
   211.78x = 210,422.89
5. Step 5: Solve for x
   x = 210,422.89/211.78
6. Step 6: Final answer
   x = 993.59