Finding the Fourth Proportional to 11,818.72, 17,731.38 and 5,155.81

Step by Step Solution

1. Step 1: Write the proportion equation
   11,818.72 : 17,731.38 = 5,155.81 : x
2. Step 2: Convert to fraction form
   11,818.72/17,731.38 = 5,155.81/x
3. Step 3: Cross multiply
   11,818.72x = 17,731.38 × 5,155.81
4. Step 4: Simplify right side
   11,818.72x = 91,419,600.54
5. Step 5: Solve for x
   x = 91,419,600.54/11,818.72
6. Step 6: Final answer
   x = 7,735.15