Finding the Fourth Proportional to 9,912.39, 13,679.10 and 5,436.05

Step by Step Solution

1. Step 1: Write the proportion equation
   9,912.39 : 13,679.10 = 5,436.05 : x
2. Step 2: Convert to fraction form
   9,912.39/13,679.10 = 5,436.05/x
3. Step 3: Cross multiply
   9,912.39x = 13,679.10 × 5,436.05
4. Step 4: Simplify right side
   9,912.39x = 74,360,271.56
5. Step 5: Solve for x
   x = 74,360,271.56/9,912.39
6. Step 6: Final answer
   x = 7,501.75