Finding the Fourth Proportional to 1,007.86, 1,390.76 and 565.82

Step by Step Solution

1. Step 1: Write the proportion equation
   1,007.86 : 1,390.76 = 565.82 : x
2. Step 2: Convert to fraction form
   1,007.86/1,390.76 = 565.82/x
3. Step 3: Cross multiply
   1,007.86x = 1,390.76 × 565.82
4. Step 4: Simplify right side
   1,007.86x = 786,922.45
5. Step 5: Solve for x
   x = 786,922.45/1,007.86
6. Step 6: Final answer
   x = 780.79