Finding the Fourth Proportional to 1,391.69, 2,087.31 and 514.61

Step by Step Solution

1. Step 1: Write the proportion equation
   1,391.69 : 2,087.31 = 514.61 : x
2. Step 2: Convert to fraction form
   1,391.69/2,087.31 = 514.61/x
3. Step 3: Cross multiply
   1,391.69x = 2,087.31 × 514.61
4. Step 4: Simplify right side
   1,391.69x = 1,074,145.54
5. Step 5: Solve for x
   x = 1,074,145.54/1,391.69
6. Step 6: Final answer
   x = 771.83