Finding the Third Proportional to 213.89 and 458.16

Step by Step Solution

1. Step 1: Write the proportion equation
   213.89 : 458.16 = 458.16 : x
2. Step 2: Convert to fraction form
   213.89/458.16 = 458.16/x
3. Step 3: Cross multiply
   213.89x = 458.16 × 458.16
4. Step 4: Simplify right side
   213.89x = 209,907.15
5. Step 5: Solve for x
   x = 209,907.15/213.89
6. Step 6: Final answer
   x = 981.38