Finding the Fourth Proportional to 9,215.51, 12,722.07 and 5,439.83

Step by Step Solution

1. Step 1: Write the proportion equation
   9,215.51 : 12,722.07 = 5,439.83 : x
2. Step 2: Convert to fraction form
   9,215.51/12,722.07 = 5,439.83/x
3. Step 3: Cross multiply
   9,215.51x = 12,722.07 × 5,439.83
4. Step 4: Simplify right side
   9,215.51x = 69,205,834.44
5. Step 5: Solve for x
   x = 69,205,834.44/9,215.51
6. Step 6: Final answer
   x = 7,509.72