Finding the Fourth Proportional to 1,007.79, 1,390.72 and 565.68

Step by Step Solution

1. Step 1: Write the proportion equation
   1,007.79 : 1,390.72 = 565.68 : x
2. Step 2: Convert to fraction form
   1,007.79/1,390.72 = 565.68/x
3. Step 3: Cross multiply
   1,007.79x = 1,390.72 × 565.68
4. Step 4: Simplify right side
   1,007.79x = 786,703.90
5. Step 5: Solve for x
   x = 786,703.90/1,007.79
6. Step 6: Final answer
   x = 780.62