Finding the Fourth Proportional to 1,036.80, 1,430.78 and 571.05

Step by Step Solution

1. Step 1: Write the proportion equation
   1,036.80 : 1,430.78 = 571.05 : x
2. Step 2: Convert to fraction form
   1,036.80/1,430.78 = 571.05/x
3. Step 3: Cross multiply
   1,036.80x = 1,430.78 × 571.05
4. Step 4: Simplify right side
   1,036.80x = 817,046.92
5. Step 5: Solve for x
   x = 817,046.92/1,036.80
6. Step 6: Final answer
   x = 788.05