Finding the Third Proportional to 189.74 and 408.59

Step by Step Solution

1. Step 1: Write the proportion equation
   189.74 : 408.59 = 408.59 : x
2. Step 2: Convert to fraction form
   189.74/408.59 = 408.59/x
3. Step 3: Cross multiply
   189.74x = 408.59 × 408.59
4. Step 4: Simplify right side
   189.74x = 166,942.47
5. Step 5: Solve for x
   x = 166,942.47/189.74
6. Step 6: Final answer
   x = 879.86