Finding the Fourth Proportional to 1,099.61, 1,647.23 and 578.83

Step by Step Solution

1. Step 1: Write the proportion equation
   1,099.61 : 1,647.23 = 578.83 : x
2. Step 2: Convert to fraction form
   1,099.61/1,647.23 = 578.83/x
3. Step 3: Cross multiply
   1,099.61x = 1,647.23 × 578.83
4. Step 4: Simplify right side
   1,099.61x = 953,457.90
5. Step 5: Solve for x
   x = 953,457.90/1,099.61
6. Step 6: Final answer
   x = 867.09