Finding the Fourth Proportional to 1,099.78, 1,648.24 and 578.46

Step by Step Solution

1. Step 1: Write the proportion equation
   1,099.78 : 1,648.24 = 578.46 : x
2. Step 2: Convert to fraction form
   1,099.78/1,648.24 = 578.46/x
3. Step 3: Cross multiply
   1,099.78x = 1,648.24 × 578.46
4. Step 4: Simplify right side
   1,099.78x = 953,440.91
5. Step 5: Solve for x
   x = 953,440.91/1,099.78
6. Step 6: Final answer
   x = 866.94