Finding the Fourth Proportional to 1,007.83, 1,390.79 and 565.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,007.83 : 1,390.79 = 565.72 : x
2. Step 2: Convert to fraction form
   1,007.83/1,390.79 = 565.72/x
3. Step 3: Cross multiply
   1,007.83x = 1,390.79 × 565.72
4. Step 4: Simplify right side
   1,007.83x = 786,800.30
5. Step 5: Solve for x
   x = 786,800.30/1,007.83
6. Step 6: Final answer
   x = 780.69