Finding the Fourth Proportional to 9,709.78, 13,399.59 and 5,518.06

Step by Step Solution

1. Step 1: Write the proportion equation
   9,709.78 : 13,399.59 = 5,518.06 : x
2. Step 2: Convert to fraction form
   9,709.78/13,399.59 = 5,518.06/x
3. Step 3: Cross multiply
   9,709.78x = 13,399.59 × 5,518.06
4. Step 4: Simplify right side
   9,709.78x = 73,939,741.60
5. Step 5: Solve for x
   x = 73,939,741.60/9,709.78
6. Step 6: Final answer
   x = 7,614.98