Finding the Fourth Proportional to 1,019.56, 1,406.88 and 571.40

Step by Step Solution

1. Step 1: Write the proportion equation
   1,019.56 : 1,406.88 = 571.40 : x
2. Step 2: Convert to fraction form
   1,019.56/1,406.88 = 571.40/x
3. Step 3: Cross multiply
   1,019.56x = 1,406.88 × 571.40
4. Step 4: Simplify right side
   1,019.56x = 803,891.23
5. Step 5: Solve for x
   x = 803,891.23/1,019.56
6. Step 6: Final answer
   x = 788.47