Finding the Fourth Proportional to 708.82, 978.18 and 394.10

Step by Step Solution

1. Step 1: Write the proportion equation
   708.82 : 978.18 = 394.10 : x
2. Step 2: Convert to fraction form
   708.82/978.18 = 394.10/x
3. Step 3: Cross multiply
   708.82x = 978.18 × 394.10
4. Step 4: Simplify right side
   708.82x = 385,498.04
5. Step 5: Solve for x
   x = 385,498.04/708.82
6. Step 6: Final answer
   x = 543.86