Finding the Fourth Proportional to 9,686.79, 13,280.67 and 9,511.83

Step by Step Solution

1. Step 1: Write the proportion equation
   9,686.79 : 13,280.67 = 9,511.83 : x
2. Step 2: Convert to fraction form
   9,686.79/13,280.67 = 9,511.83/x
3. Step 3: Cross multiply
   9,686.79x = 13,280.67 × 9,511.83
4. Step 4: Simplify right side
   9,686.79x = 126,323,475.33
5. Step 5: Solve for x
   x = 126,323,475.33/9,686.79
6. Step 6: Final answer
   x = 13,040.80