Finding the Fourth Proportional to 978.42, 1,350.15 and 558.71

Step by Step Solution

1. Step 1: Write the proportion equation
   978.42 : 1,350.15 = 558.71 : x
2. Step 2: Convert to fraction form
   978.42/1,350.15 = 558.71/x
3. Step 3: Cross multiply
   978.42x = 1,350.15 × 558.71
4. Step 4: Simplify right side
   978.42x = 754,335.56
5. Step 5: Solve for x
   x = 754,335.56/978.42
6. Step 6: Final answer
   x = 770.97