Finding the Fourth Proportional to 1,007.56, 1,390.42 and 565.42

Step by Step Solution

1. Step 1: Write the proportion equation
   1,007.56 : 1,390.42 = 565.42 : x
2. Step 2: Convert to fraction form
   1,007.56/1,390.42 = 565.42/x
3. Step 3: Cross multiply
   1,007.56x = 1,390.42 × 565.42
4. Step 4: Simplify right side
   1,007.56x = 786,165.98
5. Step 5: Solve for x
   x = 786,165.98/1,007.56
6. Step 6: Final answer
   x = 780.26