Finding the Fourth Proportional to 7,112.72, 9,815.56 and 3,968.91

Step by Step Solution

1. Step 1: Write the proportion equation
   7,112.72 : 9,815.56 = 3,968.91 : x
2. Step 2: Convert to fraction form
   7,112.72/9,815.56 = 3,968.91/x
3. Step 3: Cross multiply
   7,112.72x = 9,815.56 × 3,968.91
4. Step 4: Simplify right side
   7,112.72x = 38,957,064.32
5. Step 5: Solve for x
   x = 38,957,064.32/7,112.72
6. Step 6: Final answer
   x = 5,477.10