Finding the Fourth Proportional to 978.38, 1,467.59 and 458.09

Step by Step Solution

1. Step 1: Write the proportion equation
   978.38 : 1,467.59 = 458.09 : x
2. Step 2: Convert to fraction form
   978.38/1,467.59 = 458.09/x
3. Step 3: Cross multiply
   978.38x = 1,467.59 × 458.09
4. Step 4: Simplify right side
   978.38x = 672,288.30
5. Step 5: Solve for x
   x = 672,288.30/978.38
6. Step 6: Final answer
   x = 687.14