Finding the Third Proportional to 379.69 and 558.38

Step by Step Solution

1. Step 1: Write the proportion equation
   379.69 : 558.38 = 558.38 : x
2. Step 2: Convert to fraction form
   379.69/558.38 = 558.38/x
3. Step 3: Cross multiply
   379.69x = 558.38 × 558.38
4. Step 4: Simplify right side
   379.69x = 311,785.91
5. Step 5: Solve for x
   x = 311,785.91/379.69
6. Step 6: Final answer
   x = 821.16