Finding the Third Proportional to 143.86 and 215.16

Step by Step Solution

1. Step 1: Write the proportion equation
   143.86 : 215.16 = 215.16 : x
2. Step 2: Convert to fraction form
   143.86/215.16 = 215.16/x
3. Step 3: Cross multiply
   143.86x = 215.16 × 215.16
4. Step 4: Simplify right side
   143.86x = 46,292.21
5. Step 5: Solve for x
   x = 46,292.21/143.86
6. Step 6: Final answer
   x = 321.79