Finding the Third Proportional to 139.71 and 208.83

Step by Step Solution

1. Step 1: Write the proportion equation
   139.71 : 208.83 = 208.83 : x
2. Step 2: Convert to fraction form
   139.71/208.83 = 208.83/x
3. Step 3: Cross multiply
   139.71x = 208.83 × 208.83
4. Step 4: Simplify right side
   139.71x = 43,609.19
5. Step 5: Solve for x
   x = 43,609.19/139.71
6. Step 6: Final answer
   x = 312.14