Finding the Third Proportional to 145.78 and 208.78

Step by Step Solution

1. Step 1: Write the proportion equation
   145.78 : 208.78 = 208.78 : x
2. Step 2: Convert to fraction form
   145.78/208.78 = 208.78/x
3. Step 3: Cross multiply
   145.78x = 208.78 × 208.78
4. Step 4: Simplify right side
   145.78x = 43,589.61
5. Step 5: Solve for x
   x = 43,589.61/145.78
6. Step 6: Final answer
   x = 299.01