Finding the Fourth Proportional to 13,012.56, 17,958.96 and 7,709.40

Step by Step Solution

1. Step 1: Write the proportion equation
   13,012.56 : 17,958.96 = 7,709.40 : x
2. Step 2: Convert to fraction form
   13,012.56/17,958.96 = 7,709.40/x
3. Step 3: Cross multiply
   13,012.56x = 17,958.96 × 7,709.40
4. Step 4: Simplify right side
   13,012.56x = 138,452,806.22
5. Step 5: Solve for x
   x = 138,452,806.22/13,012.56
6. Step 6: Final answer
   x = 10,639.94