Finding the Fourth Proportional to 9,989.17, 13,782.79 and 5,739.91

Step by Step Solution

1. Step 1: Write the proportion equation
   9,989.17 : 13,782.79 = 5,739.91 : x
2. Step 2: Convert to fraction form
   9,989.17/13,782.79 = 5,739.91/x
3. Step 3: Cross multiply
   9,989.17x = 13,782.79 × 5,739.91
4. Step 4: Simplify right side
   9,989.17x = 79,111,974.15
5. Step 5: Solve for x
   x = 79,111,974.15/9,989.17
6. Step 6: Final answer
   x = 7,919.77