Finding the Third Proportional to 99.38 and 213.81

Step by Step Solution

1. Step 1: Write the proportion equation
   99.38 : 213.81 = 213.81 : x
2. Step 2: Convert to fraction form
   99.38/213.81 = 213.81/x
3. Step 3: Cross multiply
   99.38x = 213.81 × 213.81
4. Step 4: Simplify right side
   99.38x = 45,715.79
5. Step 5: Solve for x
   x = 45,715.79/99.38
6. Step 6: Final answer
   x = 460.03