Finding the Fourth Proportional to 978.72, 1,350.54 and 585.69

Step by Step Solution

1. Step 1: Write the proportion equation
   978.72 : 1,350.54 = 585.69 : x
2. Step 2: Convert to fraction form
   978.72/1,350.54 = 585.69/x
3. Step 3: Cross multiply
   978.72x = 1,350.54 × 585.69
4. Step 4: Simplify right side
   978.72x = 790,997.77
5. Step 5: Solve for x
   x = 790,997.77/978.72
6. Step 6: Final answer
   x = 808.20