Finding the Fourth Proportional to 978.17, 1,349.88 and 585.10

Step by Step Solution

1. Step 1: Write the proportion equation
   978.17 : 1,349.88 = 585.10 : x
2. Step 2: Convert to fraction form
   978.17/1,349.88 = 585.10/x
3. Step 3: Cross multiply
   978.17x = 1,349.88 × 585.10
4. Step 4: Simplify right side
   978.17x = 789,808.04
5. Step 5: Solve for x
   x = 789,808.04/978.17
6. Step 6: Final answer
   x = 807.43