Finding the Third Proportional to 139.22 and 215.77

Step by Step Solution

1. Step 1: Write the proportion equation
   139.22 : 215.77 = 215.77 : x
2. Step 2: Convert to fraction form
   139.22/215.77 = 215.77/x
3. Step 3: Cross multiply
   139.22x = 215.77 × 215.77
4. Step 4: Simplify right side
   139.22x = 46,554.80
5. Step 5: Solve for x
   x = 46,554.80/139.22
6. Step 6: Final answer
   x = 334.40