Finding the Fourth Proportional to 10,650.86, 15,986.12 and 5,389.57

Step by Step Solution

1. Step 1: Write the proportion equation
   10,650.86 : 15,986.12 = 5,389.57 : x
2. Step 2: Convert to fraction form
   10,650.86/15,986.12 = 5,389.57/x
3. Step 3: Cross multiply
   10,650.86x = 15,986.12 × 5,389.57
4. Step 4: Simplify right side
   10,650.86x = 86,158,312.77
5. Step 5: Solve for x
   x = 86,158,312.77/10,650.86
6. Step 6: Final answer
   x = 8,089.33