Finding the Fourth Proportional to 10,913.72, 16,370.56 and 3,986.60

Step by Step Solution

1. Step 1: Write the proportion equation
   10,913.72 : 16,370.56 = 3,986.60 : x
2. Step 2: Convert to fraction form
   10,913.72/16,370.56 = 3,986.60/x
3. Step 3: Cross multiply
   10,913.72x = 16,370.56 × 3,986.60
4. Step 4: Simplify right side
   10,913.72x = 65,262,874.50
5. Step 5: Solve for x
   x = 65,262,874.50/10,913.72
6. Step 6: Final answer
   x = 5,979.89