Finding the Fourth Proportional to 11,439.72, 17,130.16 and 7,924.72

Step by Step Solution

1. Step 1: Write the proportion equation
   11,439.72 : 17,130.16 = 7,924.72 : x
2. Step 2: Convert to fraction form
   11,439.72/17,130.16 = 7,924.72/x
3. Step 3: Cross multiply
   11,439.72x = 17,130.16 × 7,924.72
4. Step 4: Simplify right side
   11,439.72x = 135,751,721.56
5. Step 5: Solve for x
   x = 135,751,721.56/11,439.72
6. Step 6: Final answer
   x = 11,866.70