Finding the Fourth Proportional to 1,007.42, 1,390.22 and 565.38

Step by Step Solution

1. Step 1: Write the proportion equation
   1,007.42 : 1,390.22 = 565.38 : x
2. Step 2: Convert to fraction form
   1,007.42/1,390.22 = 565.38/x
3. Step 3: Cross multiply
   1,007.42x = 1,390.22 × 565.38
4. Step 4: Simplify right side
   1,007.42x = 786,002.58
5. Step 5: Solve for x
   x = 786,002.58/1,007.42
6. Step 6: Final answer
   x = 780.21