Finding the Fourth Proportional to 15,479.17, 21,361.34 and 8,405.59

Step by Step Solution

1. Step 1: Write the proportion equation
   15,479.17 : 21,361.34 = 8,405.59 : x
2. Step 2: Convert to fraction form
   15,479.17/21,361.34 = 8,405.59/x
3. Step 3: Cross multiply
   15,479.17x = 21,361.34 × 8,405.59
4. Step 4: Simplify right side
   15,479.17x = 179,554,665.89
5. Step 5: Solve for x
   x = 179,554,665.89/15,479.17
6. Step 6: Final answer
   x = 11,599.76