Finding the Fourth Proportional to 1,118.56, 1,678.24 and 571.20

Step by Step Solution

1. Step 1: Write the proportion equation
   1,118.56 : 1,678.24 = 571.20 : x
2. Step 2: Convert to fraction form
   1,118.56/1,678.24 = 571.20/x
3. Step 3: Cross multiply
   1,118.56x = 1,678.24 × 571.20
4. Step 4: Simplify right side
   1,118.56x = 958,610.69
5. Step 5: Solve for x
   x = 958,610.69/1,118.56
6. Step 6: Final answer
   x = 857.00