Finding the Fourth Proportional to 9,986.71, 13,782.33 and 5,739.15

Step by Step Solution

1. Step 1: Write the proportion equation
   9,986.71 : 13,782.33 = 5,739.15 : x
2. Step 2: Convert to fraction form
   9,986.71/13,782.33 = 5,739.15/x
3. Step 3: Cross multiply
   9,986.71x = 13,782.33 × 5,739.15
4. Step 4: Simplify right side
   9,986.71x = 79,098,778.47
5. Step 5: Solve for x
   x = 79,098,778.47/9,986.71
6. Step 6: Final answer
   x = 7,920.40