Finding the Third Proportional to 99.51 and 218.16

Step by Step Solution

1. Step 1: Write the proportion equation
   99.51 : 218.16 = 218.16 : x
2. Step 2: Convert to fraction form
   99.51/218.16 = 218.16/x
3. Step 3: Cross multiply
   99.51x = 218.16 × 218.16
4. Step 4: Simplify right side
   99.51x = 47,594.71
5. Step 5: Solve for x
   x = 47,594.71/99.51
6. Step 6: Final answer
   x = 478.29