Finding the Fourth Proportional to 15,559.31, 21,471.86 and 8,485.79

Step by Step Solution

1. Step 1: Write the proportion equation
   15,559.31 : 21,471.86 = 8,485.79 : x
2. Step 2: Convert to fraction form
   15,559.31/21,471.86 = 8,485.79/x
3. Step 3: Cross multiply
   15,559.31x = 21,471.86 × 8,485.79
4. Step 4: Simplify right side
   15,559.31x = 182,205,608.72
5. Step 5: Solve for x
   x = 182,205,608.72/15,559.31
6. Step 6: Final answer
   x = 11,710.39