Finding the Third Proportional to 208.69 and 278.72

Step by Step Solution

1. Step 1: Write the proportion equation
   208.69 : 278.72 = 278.72 : x
2. Step 2: Convert to fraction form
   208.69/278.72 = 278.72/x
3. Step 3: Cross multiply
   208.69x = 278.72 × 278.72
4. Step 4: Simplify right side
   208.69x = 77,684.14
5. Step 5: Solve for x
   x = 77,684.14/208.69
6. Step 6: Final answer
   x = 372.25