Finding the Fourth Proportional to 1,007.55, 1,390.27 and 565.39

Step by Step Solution

1. Step 1: Write the proportion equation
   1,007.55 : 1,390.27 = 565.39 : x
2. Step 2: Convert to fraction form
   1,007.55/1,390.27 = 565.39/x
3. Step 3: Cross multiply
   1,007.55x = 1,390.27 × 565.39
4. Step 4: Simplify right side
   1,007.55x = 786,044.76
5. Step 5: Solve for x
   x = 786,044.76/1,007.55
6. Step 6: Final answer
   x = 780.15