Finding the Fourth Proportional to 9,911.12, 13,676.36 and 5,720.72

Step by Step Solution

1. Step 1: Write the proportion equation
   9,911.12 : 13,676.36 = 5,720.72 : x
2. Step 2: Convert to fraction form
   9,911.12/13,676.36 = 5,720.72/x
3. Step 3: Cross multiply
   9,911.12x = 13,676.36 × 5,720.72
4. Step 4: Simplify right side
   9,911.12x = 78,238,626.18
5. Step 5: Solve for x
   x = 78,238,626.18/9,911.12
6. Step 6: Final answer
   x = 7,894.02