Finding the Fourth Proportional to 978.56, 1,468.11 and 871.10

Step by Step Solution

1. Step 1: Write the proportion equation
   978.56 : 1,468.11 = 871.10 : x
2. Step 2: Convert to fraction form
   978.56/1,468.11 = 871.10/x
3. Step 3: Cross multiply
   978.56x = 1,468.11 × 871.10
4. Step 4: Simplify right side
   978.56x = 1,278,870.62
5. Step 5: Solve for x
   x = 1,278,870.62/978.56
6. Step 6: Final answer
   x = 1,306.89